It'a not a matter of 'someone snuck in and changed things'. Picture this;
You did 87 edits in the previous 5 days of running RB (without reboot) then let it go to sleep. Some memory location got lost. (Exception error expected)
Question is did you change any settings to try to fix it before simply rebooting? In the frustration I probably would have so suspect you may have.
If so, those settings got saved and now you have an issue. I'm not saying this to sound like a pain, but rebooting before every session can save a lot of headaches. I learned that the hard way (but that's in the past on this issue).

Start over. Reset RB to default settings. Rename Realband.INI and RB.CFG files (in C:\Realband) so RB resets itself and rebuilds those files. This resets the program as far as soundcard discovery/settings. Then set up correct drivers in RB for MOTU. See if that helps.

Again; the issue with track 1 input (in ASIO) being overpowering is likely inside the MOTU software mixer (not RB). Been there done that. Look everywhere in MOTU software applet for any routing that may feed the track back in. This part can be complicated in the best software mixer routing, so be patient and look.

That said, what you are attempting should not require ASIO. Staying in MME would be more stable, as long as the needed output/input ports showed up in RB drivers section while choosing MME.
If not it is the MOTU forccing ASIO, not RB. If they are available RB will use MME (wdm) drivers. If they are not available (and the card requires ASIO) then you have to go that route, it should still work.

I do not work here, but the benefits are still awesome
Make your sound your own!