Enque backup file grows - why?

Greetings.

Enque backup file(ENQBCK) has enormous size (aprox. 700Mb) and continues to grow.

Even there are no canceled or current updates in the system this file doesnt clean itself after system restart so the system starts half an hour.

Have any clue?

R/3 4.7/200

kernel 6.40 patch level 247.

Thanks in advance,

Mihail Groshev.