I've fixed some errors and improve test reliability, however for some tests I was not able to identify causes of the failure. Locally they are working just fine and remotely (on TC) from time to time there is an error (I was not able to determine the cause of the issue).

Most likely to fail were tests from TestOfflineMessageDeliveryAfterSmResumptionTimeout related to delay between authentication and resource binding. That is very rare situation and as I was not able to replicate the issue locally and find what is causing that I've decided to ignore those tests for the time being.

I have no idea, what could be improved to deal with the remaining issues which are happening from-time-to-time.

OK, let's ignore it for now, though it would be better to fix heisenbugs but this seems to be very low occurrence / priority.