Have the relay contacts OPEN when a limit is hit.
1. The NC position of relay stop floating inputs picking up stuff. Nice antennas when open?
2. If a limit wire breaks during operation, it will just continue like nothing happened, and not trip on limit.
3. Debounce value around 1000-2000. Wants to be about 1 mains cycle or more.
4. Your ribbon cable is running parallel to the red/white twisted cable. It is also right on top of a power transformer!
Try to separate them and see if that makes a difference.
5. Where is your common star ground point? I see various cables under multiple bolts.
Temporarily disconnect ALL of them and tie them to a common point and to ONE ground point. IMPORTANT!!
There should ideally only be ONE ground point to the chassis for the whole machine.
6. What are the two yellow wires going to middle lower edge of the BOB? Might be a nice antenna.
If after converting to NC operation you still have a problem then disconnect limit wires at BOB and bridge them with links and see if it still trips.
If so it is getting into the BOB elsewhere. Does the BOB have a micro?
The wire to the relays should have a shield, only connected at the BOB end.
Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. Three ways to fix things: The right way, the other way, and maybe your way, which is possibly a faster wrong way.