Since February 4th, 2021 Caliber is using an automatic player ban system. If you think that in your case the ban was applied erroneously, you can make an appeal:
In one of the upcoming updates we'll add Player ID display to the game client. At present, it can be found in the logs, following the instructions below.
Unfortunately, the automatic system cannot discern the reason why you disconnected from the battle, be it conscious deserting or technical issues. We increased the time you have to return in order to minimize the amount of erroneous punishments. Right now, in order to avoid a penalty or a ban, you have three full minutes to return back to the battle.
If you keep encountering technical issues that lead to freezes and crashes, please contact support.