Client can't connect to server on MAC OS after updating to Catalina

There is NextCloud client on MAC and after upgrading to Catalina it is not possible to connect ti server. Client gives error 504 Gateway time-Out.
It works perfect on other Macs with previous OS, but doesn’t on Catalina. Is there any idea why it happens?

Nextcloud server ver. 15.0.7

Hello @ravolar and welcome to our community.

Please provide client version.

Have you checked client log file?
Have you checked server log file?

Client version is 2.6.0, the last one avalable for download. I reinstall client to last version and also get this error when try to login.
There is no any logs about this connections, if I check it from WEB interface.

I have not installed the new NC client 2.6.0 on Catalina due to errors with the code signing certificate - the previous client runs just fine on Catalina on my MBA.