account randomly logged out by itself (firefox). therefore my IDM can't download anymore (file not found) and i had to manually login again.

i just experiencing (for few days) that my other account randomly logged out by itself (firefox). therefore my IDM can't download anymore (file not found) and i had to manually login again, and then recapture link from firefox, and start the IDM download again.
can you fix this? coz i never use another machine/handheld to login using that account.