SAT1 was closed initially when we went into the first lockdown. The TTS was totally switched off then as well so all passengers walked to SAT2 and all arriving internationally passengers where buses to immigration.
SAT1 and TTS reopened for the summer and SAT1 closed in early September. The TTS still is running to SAT2 for international flights.
SAT3 was also originally closed in the first lockdown and reopened for the summer. SAT3 is still open now.
There was talk that the talk that the TTS would be switched off early winter as their wasn’t demand to be running it to SAT2. So if this happened all SAT2 flights would require passengers to walk there.