No connectivity after enabling mps and using splitter - works fine when MPs not enabled and directly connected - 2500D

I have two 2500D adapters, that are working fine without mps enabled, using a new Splitter.

but, when I enable mps, the network stops connecting (mps Light solid on both, lan is not). turning off mps brings everything back.

for troubleshooting, I tried connecting directly though a single cable and everything works fine with mps enabled.

using a bamf splitter off Amazon that says it is moca compatible/saw on Lon.tv.

any ideas ?