Can't progress to new Civilization level after patch 1.3.4

[Pijukatel]

Hello, first thanks for the update and nice list of fixes. And really good single trading goods visualization!

On the other hand I have experienced a new, never seen before issue in ongoing multiplayer game (not some old game.) I can't progress to a new Civilization level.

I am "glorious", I have 5 progress tokens and 13 regions. I should be able to progress from level 2 to level 3, but the progress button is missing.
(See attached screenshot.)

[Pijukatel]

There will be multiplayer save available until Friday, if you want to check that.

[Surt]

You need 20 regions in Persia DLC, you should get an log entry or a <whatever those popups on the right of the screen is called>.

[Pijukatel]

Thanks for info, I was not aware of that.

[Pocus]

Thanks for info, I was not aware of that.

Each time you can progress but are blocked by this limit, there is a message in the log (top priority)