Electrical Problems? Very frustrating

I have a Sabre 1646 that is having electrical issues.

It normally starts right up and then last year it just clicked with no turn of the starter.
To troubleshoot I tried jumping the selenoid, nothing. I tried another battery. Nothing. Put in a new starter, it actually cranked but still not enough to start.
So I jump started it with the car to get it going.

This year I thought, maybe that was an old battery they sold me. I picked up another one with more CCA's and have had a carefree experience all summer so far.

Then today, same thing. Battery shows good charge although it does drop when I turn the key.
This time I jumped the selenoid and it started right up.
However, now when I release the brake it shuts off immediately.

Connections look good everywhere.

I zip tied the switch to detect that the brake was on always , it starts and moves fine now however NOW ...
when I engage the PTO it stops suddenly. When the pto is engaged, the switch actually releases vs being depress as it is with the brake. So it's not stalling, it's being shut off.

ANY suggestions here?