Yup. Will check with another login...

Ah - I'm connected with NordVPN at the moment (traveling), perhaps it's auto-disabled on that?

Also not there with another account with clean settings, in a private window. I definitely suspect my VPN as being the cause now, though!

Although, I can thank people on enwiki (and just did so), so maybe the VPN isn't the only cause... Odd!

In T344056#9086675, @Mike_Peel wrote:

Although, I can thank people on enwiki (and just did so), so maybe the VPN isn't the only cause... Odd!

You're an enwiki admin, which would let you bypass IP blocks there.

In T344056#9086692, @taavi wrote:

In T344056#9086675, @Mike_Peel wrote:

Although, I can thank people on enwiki (and just did so), so maybe the VPN isn't the only cause... Odd!

You're an enwiki admin, which would let you bypass IP blocks there.

Ooh, good point - that also explains Commons. Checking on the Wikimania and en.wikisource wikis, there are no thanks links there either. So maybe it's working as intended, but it's really non-obvious to VPN users (no notices etc.)?

(Edited task description accordingly, I hope that helps.)

I think this is not a bug, but a feature. Just as with other active features, MediaWIki tries to respect blocks in all places where reasonable, including thanks. Prohibiting VPN editing is technically implemented via blocks. Although possible, I think it is not desirable to bypass blocks in Thanks, as we had places where attackers deliberately misused thanks to annoy participants.

What could make sense is including the thanks link in a greyed/struck way, so it is clear that it cannot be pressed, and have a clear information in the title field or something, that'd inform the user why they're unable to thank users.

Explaining it to the user would definitely be an improvement. Respecting blocks is important though, although it's not obvious when it's still allowed to have access despite the VPN block and then not be able to do certain things without explaination.