MIDI Sync issues with Walrus Audio D1 stereo delay v1

Hi I currently have my MPC1000's MIDI out Port A connected to D1 v1's MIDI in, then I have MIDI out (thru) of D1 v1 and goes into Dreadbox Nymphes' MIDI in. MIDI clock is coming out of the MPC1000 through Port A only:

Sync Out = Master
Mode: CLOCK
Frame Rate: 25
Send MMC: OFF

I was able to sync the Nymphes' LFO with no issues but for some reasons I cannot make the D1's tempo to sync. I have JJOS2XL running. Pls advise, thx.

Bump and some quick updates: so I've been chatting with Walrus Audio guys and they are scratching their heads as well.
Setup:

MPC1000 MIDI A OUT -> D1 delay pedal MIDI IN -> D1 delay pedal MIDI OUT/THRU -> Nymphes.
In the SYNC menu of JJOS2XL, I have the MPC as the clk master, outputting on both A and B MIDI ports.
For whatever reasons. the delay pedal does not want to sync to MPC but the Nymphes was able to sync to MPC with no problems and it's sitting downstream from the D1 pedal!?

Changing frame rates (24, 25, 300, 30) doesn't make a difference. Flipping MMC on/off doesn't make a difference. I wonder if I'm missing something obvious...
However, if I replace the MPC with a keystep 37, the D1 pedal is able to sync to keystep's clk no problem.

Update: Well the D1 delay pedal finally sync'ed to the MPC1000's clk by adding a synth module in between the MPC and the pedal: MPC1000 (MIDI OUT) -> (MIDI IN) DreadBox Typhon (MIDI OUT/THRU) -> Walrus Audio D1 delay.
Not sure why it worked but it worked... maybe the Typhon either cleaned up / boosted / delay the clk in a way that is now recognized by the delay pedal? I'm still using 24 frame and have not changed any MPC MIDI/CLK settings since my last update.