1 proxy for 2 accounts = Cut FL activity by five time ?

Hi everyone,
To optimize my costs I started using 1 proxy for each 2 accounts since last month.
But here is the thing : my activity on follow liker is like 5 times slower now.
Instead of liking 500 pics/day, they only like 100/day, even though I use the same settings as before.
I checked the activity log and no fail or error.
Where the this slowness can come from ? Is it normal when you share your proxies among other accounts ?
Thanks

it's not normal unless the proxy is slow to begin with and you try to perform more tasks at the same time, but even then if a task fails for any reason, e.g. timeout error, you should see that from the error log i believe, although i'm not using FL anymore
maybe something is off with your settings