Did you change anything?
When you have PG harvest proxies it is still finding public proxies which are liable to go dead at any moment which is why it is very important to have it checking for proxies almost non-stop to ensure that you have working proxies the whole time. This is why I was stressing the fact that in the PG log you should see it updating the list every 15mins max, if it is updating less often than this then set Interval to 0 and make sure it is only searching for about 50 proxies so it isn't spending too much time looking for new proxies while the ones it has already found are going dead.
Google verified proxies aren't necessary so don't enable this as PG will spend far too much time looking for proxies. I also set the file to overwrite so you do not have old proxies sat in there that no longer work.