I have bought an expired domain at the beginning of June. The domain was still ranking for ~150 keywords in Google and before it had like 9-10k keywords with about 10k traffic.
So I bought this domain, and firstly just restored the site from webarchive. Semrush instantly started showing more keywords popping up in the SERP in a matter of hours. Seeing this, I moved the site to WordPress (generatepress theme) and a few days later added it to Search Console. Here's data from it:

As you can see, impressions are down completely. From 1,8k on June 11 to just 40 on June 13 and later. This is also reflected by Semrush: a few days before it was showing 3k keywords (from just 150) and now this number has fallen to 2500 and continues to fall.
So here I am now wondering what to do and what has gone wrong?
Is this related to the change of theme and I shouldn't have put the website on WordPress? Should I have waited unless most of positions the site had before I get and only then move it to WordPress? Cause I as say, before I changed the site from the last Webarchive-restored version to the Wordpress, the number of keywords was growing and growing and after the change it just went "pooh!". Should I have added the website at all to search console (lol)?
Here's another domain I have acquired in mid-late April:

The history of it is somewhat similar but not exactly the same. The number of keywords it was ranking for before got dropped was about 1k, but the gap between the time the domain wasn't continued and I bought it is roughly the same (~2 months). However, after restoring the site I haven't instantly (almost) changed it to WordPress and it was sitting on its old theme with missing images and some useless posts - the site before was already used by someone as PBN, but no casino, viagra, bad anchor links etc.
It took me a few days in May to move the site to WordPress (generatepress as well) and I finished doing it on May 19. On May 21 I have installed search console as you can see above. On May 25th you can see the first drop in impressions (halved them), on May 31 the second big drop (again, from ~350 to 140) and on June 1 the third one which finished the site and now it has only 40 to 50 impressions per day with ~300 keywords in google. However, compared to the first site the fall wasn't instantaneous and happened throughout a few days and not one.
I also added some a few articles in late May - early June, but it seems irrelevant.
However, the second site could've been destroyed by the same filter the second one got killed. Both sites:
-Use the same theme
-Were killed by after installing the WordPress theme.
However, there is also a time difference. I finished installing WordPress and putting content the site #1 on June 9. On June 11 put it to Search console, the next day impressions are halved, on June 13 the site is finished. When it comes to the site #2, after moving it to WordPress it was ok a few days and then impressions halved, a few more days of stable impressions and then destroyed. That's why I'm inclined to believe this second site was destroyed by the May update while the first one got taken out by some usual filter.
What do you think? I don't want to lose site #1 (the second one is worse anyway), it had nice traffic before. What would you do in this situation?
So I bought this domain, and firstly just restored the site from webarchive. Semrush instantly started showing more keywords popping up in the SERP in a matter of hours. Seeing this, I moved the site to WordPress (generatepress theme) and a few days later added it to Search Console. Here's data from it:

As you can see, impressions are down completely. From 1,8k on June 11 to just 40 on June 13 and later. This is also reflected by Semrush: a few days before it was showing 3k keywords (from just 150) and now this number has fallen to 2500 and continues to fall.
So here I am now wondering what to do and what has gone wrong?
Is this related to the change of theme and I shouldn't have put the website on WordPress? Should I have waited unless most of positions the site had before I get and only then move it to WordPress? Cause I as say, before I changed the site from the last Webarchive-restored version to the Wordpress, the number of keywords was growing and growing and after the change it just went "pooh!". Should I have added the website at all to search console (lol)?
Here's another domain I have acquired in mid-late April:

The history of it is somewhat similar but not exactly the same. The number of keywords it was ranking for before got dropped was about 1k, but the gap between the time the domain wasn't continued and I bought it is roughly the same (~2 months). However, after restoring the site I haven't instantly (almost) changed it to WordPress and it was sitting on its old theme with missing images and some useless posts - the site before was already used by someone as PBN, but no casino, viagra, bad anchor links etc.
It took me a few days in May to move the site to WordPress (generatepress as well) and I finished doing it on May 19. On May 21 I have installed search console as you can see above. On May 25th you can see the first drop in impressions (halved them), on May 31 the second big drop (again, from ~350 to 140) and on June 1 the third one which finished the site and now it has only 40 to 50 impressions per day with ~300 keywords in google. However, compared to the first site the fall wasn't instantaneous and happened throughout a few days and not one.
I also added some a few articles in late May - early June, but it seems irrelevant.
However, the second site could've been destroyed by the same filter the second one got killed. Both sites:
-Use the same theme
-Were killed by after installing the WordPress theme.
However, there is also a time difference. I finished installing WordPress and putting content the site #1 on June 9. On June 11 put it to Search console, the next day impressions are halved, on June 13 the site is finished. When it comes to the site #2, after moving it to WordPress it was ok a few days and then impressions halved, a few more days of stable impressions and then destroyed. That's why I'm inclined to believe this second site was destroyed by the May update while the first one got taken out by some usual filter.
What do you think? I don't want to lose site #1 (the second one is worse anyway), it had nice traffic before. What would you do in this situation?