Intermittent availability of alchemy in Elysium taverns

[Weirdomen]

As soon as either one of my characters Peter or Walter peform alchemy at a tavern in Elysium (a benefit of The Enduring City), the option to perform alchemy at that tile disappears for a while.
When Walter performs alchemy at (8,18) and loses the option temporarily, Peter at (17,5) still has it available, so this inability to use alchemy isn't global over all the plane.
Talking with Aulë's player, when I don't see the option, they don't see it either, so it's not character-specific.
From this, it seems like the effect is... tavern-specific?

The option seems to reappear after a few minutes, but not exactly at a new tick (e.g. was lost at 11:21:38 and reappeared at 11:31:29).

The option sometimes isn't there even when my characters haven't acted yet, but besides random on-off switches, perhaps another character might have done something that triggered the disappearance.

I haven't tested if other buildings affected by The Enduring City also lose their perk.

[Kandarin]

The issue was that infusion (and thus any XP gain) was overwriting tiles with the base traits of their tile type. In Elysium, The Enduring City overwrites taverns with alchemy ability (which the base tile traits for Taverns lack) but it was getting replaced every time someone earned XP, only to get restored on the next AP tick.

There's a pending fix for this for the next patch.