I am using FF and the google translate addon.
If I visite a site, I right-click:
translate.google.com is blocked.
In the query log I mark
translate.google.com shows up in whitelist with entry comment "Added from Query Log", action is working fine word will be translated.
I CHANGE the "Added from Query Log" to a diffent naming, close the browser and translate.google.com is blocked DESPITE showing up as whitelisted.
Seems the non-standard comment is doing "something" to block the site, same game again, if I whitelist via query log with standard comment (Added from Query Log) - site is really unblocked again.
The original Blacklist/Whitelist menu entries pre-date Pi-hole's group management, and they have been left merely as a convenience feature, to gently nudge users to get familiar with Pi-hole's (then new) group management feature set.
They are indeed not handling Group Assignment correctly.
Fortunately, that can be completely avoided by exclusively using Group Management|Domains for managing your domains.
Please use that UI also to readjust the Default group assignment.