Problem bug with midi mtc synchro When Looping Cubase 11 and 12

Hello Guy,
Nice to join Today thé Cubase communauty. Im old user : I had my first Cub on atari 1040 back in the days … Today 25 years Im Always here but … maybe not for long. I dont want to change DAW because Im Cubase lovers… But its unbereable to fight such kind of sync problem in 2022. Back in the days, with an Atari, it was possible via midi to run a drum machine and to perfectly run it with Cubase…

25 years later , with a PC who have AMD5 full SSD and win11 and Cub12, its seems to be impossible to drive correctly a simple MTC to Sync an arpeggio, a external seq (hardware and software) or a drum-machine…

The sync could be put on but When a loop is activated with locator, the sync Failed When the loop end to restart…

I try thousands of things to investigate this problems. I try other softwares and DAW and never have this bug. I try another midi card, another Asio drivers etc…

Nothing to do ? I read on Google many users had this problem and its a 100÷ Cubase own bug…

The problem is very huge because so reccurent and let Cubase to be useless tools…

But im Cubase lovers, dont want to quit… So im looking for solution.

Did someone Heard about this bug ?