Try taking the DI out of the signal chain. The Stomp's Outs are already BALANCED, so not necessary.
If it works, and you NEED XLR, get a 1/4" balanced to XLR adapter.
"at last iteration of this same setup I had a TONEX One where the stomp goes and it was dead-quiet. "
The ToneX Out is INSTRUMENT level, so set the Stomp's outs to INSTRUMENT.