License problem after rb 133c reset and reflash

I’ve a routerboard 133c and I see from winbox the mac address of my board only for 1 second and after nothing.
I connect a serial cable to the routerboard and i see…
starting services…

stoping services…

then I reset with jumper my rb but no result…
now i reflash this rb 133c and the system now is on but…
the license is invalid and I Have 24h to purchase a valid key…why?

When i reinstall the routerOS i from netinstall i see “ (92f/9/2b/9n… etc”

i guess one of my customers have this problem as well; altough i dont know the exact details he said the winbox has deactivated the menus; and closes itself automaticly after some time. any reason for that? the board has L5 licence ; i have recently upgraded the ros frimware, installed ros 2.9 on it and when i checked the system from winbox the license was there; any ideas & help ??