Trouble to opening t.co links I have trouble to open links from Tweetbot in Safari on the Mac. it just waits loading with the t.co domain.

On iOS I don't have this problems!

Is it because I use uBlock as an adblocker? I can not reproduce this problem. After opening the link a second or third time it usually works.
It is possible that it has something to do with uBlock. Have you tried disabling the extension temporarily? Try that and see if the problem persists, if it doesn't, then that is your answer. You might just need to whitelist the domain t.co.

If it doesn't solve the problem, then you might need to try something else. Is both your Mac and iOS device on the same WiFi network? There could be a firewall or something blocking the Mac from connecting to the domain, while the iOS device is on cellular data.