fasttrack dummy rules

my RouterBOARD 962UiGS-5HacT2HnT behaves strangely:
I’ve first booted it up a month ago, then i configured it using webfig it worked great for a day or two.
then I’ve tried WinBox and on the first connection it asked my something about resetting my configuration to the default values, I’ve said no and then I’ve had a look at the various menus.
a few hours later I’ve noticed something strange, my connection wasn’t working anymore and I couldn’t connect to the router anymore.
using MAC protocol I’ve accessed the router in WinBox and I’ve found out that the switch was gone and so my PPPoE settings.
then I’ve rebuilt the switch with eth2 as master port, but now the name is no more eth2-master but only eth2 and I’ve reconfigured pppoe and so.
then, a week ago I’ve found out that a few filter rules changed themselves from forward chain to input chain (I have to admit that those rules where initially input rules, backed up with the Files menu in WinBox and then putted in the flash folder for some reason, then I’ve changed them in forward rules and after a reboot went back, autonomously, to input rules; after that I removed the backup from the flash folder, maybe the backup file in the flash folder gets automatically restored as working config on reboot?)
anyway, I’m noticing now that the fasttrack rules in Filter and Mangle are gone and in mangle I’ve two rules, action “change MSS” setted up.
I have no memory of creating them, but maybe they’re the result of the OVPN server I’ve set up a few weeks ago.
now, I’d like to recreate the fasttrack rules in Filter and Mangle, any help?
thanks.