Sync clients stop working after trying to access whit Lightning plugin in Thunderbird

Good morning.

I have discovered a bug I believe but I’m not quite sure. Yesterday I tried to setup contacts and calendar in Thunderbird and it ended whit sync clients not working any more. Last lines in log are:

{“reqId”:“um1QbENr22vGJ2axxM2Y”,“level”:2,“time”:“2018-08-21T02:17:54+00:00”,“remoteAddr”:“”,“user”:"–",“app”:“core”,“method”:“PROPFIND”,“url”:"/remote.php/dav/",“message”:“Login failed: ‘’ (Remote IP: ‘’)”,“userAgent”:“Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 Lightning/5.4”,“version”:“”}

and I’m not able to connect whit Windows sync client and not whit Davdroid also. WebDav connection can be established whit Cyberduck for example. Windows sync client shows “No connection to https://yada, Operation cancelled.” This issue was active for 12h and fixed by itself. I restarted services and whole server and nothing did not work.

Please advice.