I've been driving hard these days plus long waits in traffic, suddenly the gear seems to be giving this error for the last two weeks, displays gear lever not engaged properly and shifting into reverse or park gets too hard to move. there is no transmission oil leak, the engine heat level is normal, what needs to be fixed here and thank you all in advance

 

I've found some info on this, could this be it?
an ECU reflash and MAF solved all the rough running ?