I keep failing to reproduce this one since quite a while now (playing for 1.5 hours as client).
I did built stuff on almost the entire map I even get some lags now, but the Alchemy Lab does not want to break for me.
And (as with the bugged rally flag cancel icons for client) also here we had a similar internal bug report before which was fixed and this fix should be in current public version.
So for me it is important, that you are not in a Beta Branch on Steam which might be outdated?
If not, did you do anything specific when using the potions?
Did you grab them via UI or directly from the cauldrons?
Did you apply them in any unusual way or at an unusual place?

This was one of the weirdest timing issues I ever encountered.
But the problem was that the servers current state was unclear when the clients request for the ritual arrived.
So it could happen that the cool down on server did not yet start or was not yet over.
Additionally the current ritual did stop it self a tick later than it was replaced by the client and thus stopped the new ritual on server while the client was thinking it would still be there.
And while debugging the order of events got changed, so that it was hard to debug.

Now all cases of off timings between client and server are handled properly.
From next patch this should not happen again.

Thanks for reporting.

At least the cancel rally bug is an old one we had some months ago and it should really be fixed.
Now I wonder if you are maybe checked into an old beta branch? (Properties -> Betas)

You should be able to do that in single player or as host otherwise I start to believe your game must be corrupted because I promise it works fine for me, however I did not test public version.
But even in internal version client ritual start while sanctuary is in cooldown is broken.
And I am right now on fixing this.

We must have fixed that internally meanwhile but not pushed a new build containing this fix.

Yea I understand, but in my screenshot I played as client and had this cooldown visuals.
So this part works for me, what does not work occassionally is that cultists sometimes ignore the new ritual, when it was queued during cooldown for the client.

Looks like the client and server both run the cooldown, but for some reason the clients one is just a split second faster.
So the client tries to start the ritual on server too early while the server is still in cooldown and thus denies the request.
So we will have to refactor a bit how this works to make sure there is no timing issue.

I avariced quite a lot and this during the cooldown the first two times it worked, then no one cared about the ritual unless I canceled and restarted it after the cooldown.
So there is some kind of bug.
Btw. it is intended that the player can select a new ritual during cooldown, it simply just starts once the cooldown is over.
However for client this queuing seems broken or not working reliably.
We are investigating why.