Hello dears.
I have a hAP mikrotik routerboard and OS version is 6.48.1 (recently updated) and now have a big problem: after resetting password to my favorite, it gets back to default password (blank)! I checked Logs but there is no suspicious activity there! and in Scripts and Scheduler too!
one more thing: sntp change time is occurring repeatedly(Log)!

• create a supout.rif file
• export (not backup!) the configuration to a file, and download that file to some external machine
• netinstall the device with 6.48.1
• check whether the issue continues
• if yes, netinstall it again with 6.47.9; if the issue is still there, raise a warranty claim for the device if still within warranty period, because it must be a hardware issue in such case
• if not, re-create the configuration using the exported file, open a support ticket and attach the previously created supout.rif file to it, as the issue may have been caused by either some bug in the upgrade process or by some malware that squatted in at a level which is not visible from the RouterOS configuration. And post the configuration export here (see my automatic signature regarding anonymisation), maybe your firewall rules were too weak.