5.2i & DOS 5.12 by mr Gluk

I flashed my own firmware, and discovered one glitch.
When running some programs from 5.2i (for example
F-Commander4.01), this same commander is buggy, falling out into
BASIC. If you cut off the int from the processor (I have a button), then this glitch does not appear. The same problem occurs when using Faultless
number 8. If you select an article and then quickly cut off the int before it starts to unpack, then everything is OK, as soon as you return the
int, it immediately falls out into BASIC.
Who here has encountered this? Please answer!!!

See you. Jan Zagorskikh.