ive pushed an update that should switch back to original proxy for this case, can you try again?

yeah i was able to confirm as well with vpn its restricted since im in the netherlands. deleting and reviewing is the same as editing and reviewing, to potentially refresh the proxy server used to fetch game info you have to rejoin.
it chooses to use the second proxy server (the one i run personally) if it fails on the original proxy too many times (which should just use whatever server region the roblox server is in), likely related to busyness of bd usage at that moment since it tends to block up when too many people use it at once.
think it should be fixable by retrying on the original proxy if it gets no data from the second proxy

I tried editing my review again and it gives the same error, and about the restrictions it's banned in Belgium, The Netherlands, UK (for under 18) and Australia, i'm going to try to see if i can delete it and review the game again.

from a bit of figuring out it is indeed public and playable for others, but not for me, so might be a case of law restrictions taking place but no idea what that could be.
winter (mod in the discord server) was able to review it, you could try again and hope it doesnt switch over to the second proxy server, which is my server and has the restriction. i think it should be in your reviews still as orange text.
its either that or its age verification gated, in which case that would be impossible to fix.

yes

roblox.com/games/388599755/POLYGUNS

are you sure the game is public? im unable to open it on roblox, gives me a 404 error

I was trying to update my review about the game POLYGUNS (ID: 388599755) and a text showed saying "Unable to retreive game data! This is either an issue with the game or a ROBLOX issue.", the game is public and had no issues and Roblox isn't down.