I'm not quite ready to call it fixed but I got all my bands back!
I found the MOSFET that controls 20M(I think Q5) was faulty. The output from the microcontroller would only come up to 2.1V instead of 3.3V on the 20M band line. When powered off I found less than 100Ohms between the pins on Q5 where Q4 and Q3 would be in the megaohm range.
After removing the faulty MOSFET the voltage from the microcontroller reached 3.3V as expected. I then swapped the MOSFET from the 40M filter over to the 20M position. I put firmware 1_10 back on and all the bands stayed!??
I'm not sure what caused the issue and I'm not convinced there aren't still other problems but I have a clear path forward now. I'll be ordering some BSS123s. If I find anything else which might be helpful I'll post back here for anyone who might see something similar in the future.
