Logs shows that mega responds with *no more quota available*
Without Account it answers
HTTP/1.1 509 Bandwidth Limit Exceeded -> results in 'IP Blocked' message because mega tells how long to wait
With Account it answers the same
HTTP/1.1 509 Bandwidth Limit Exceeded -> results in account being temp. blocked/disabled
then out of sudden, mega allows download via account again and log shows many downloads of smaller 7-14mb files
to me it looks like the downloadserver you're trying to download is causing the issue. in case both (non account and account) are receiving the *509 bandwidth limit* error, the final download comes from same mega server.
I can do further testing but I need username/password and example links. Can you send them to
support@jdownloader.org ?