Unfortunately the bug still exists in 22.214.171.124 EA on my Xperia 10 II.
Indeed, it takes almost exactly 150 seconds (2,5 minutes) to reconnect (SFOS 126.96.36.199, Xperia 10 ii, Telekom Germany). That is way too long.
Incoming call causes switching from 4G to 2G and thus cuts mobile internet. Once the call is finished, reestablishing a data connection with 2G takes more than a minute. However, the 2G data connection is automatically cut after a few seconds and for little less than 1,5 minutes no network access at all exists. Only thereafter 4G is back.
I’ve been able to send some Video and Logs of that to Jolla. Also I detected, that this only happens to me if WiFi is off. Reproducible. What i didn’t test, is the condition that WiFi is on but no network available. Perhaps someone can confirm that as well.
By the way, i think mine connects back in like in 36 sec or so.
Indeed, in my test I switched Wifi off. Reconnection depends on the quality of the mobile network. In our office the network is weak. This could be the reason why restoring mobile data connection took so long.
However, the steps are always the same: falling back to 2G for a voice call, after the call reestablishing a first data connection with 2G, then killing all mobile network access completly and eventually establishing a new 4G connection.