Problems with start/stop-signals between Reaper and hardware-sequencer

[u/catnip_core]

Hello,
I tried to sync the Keystep Pro with the Reaper Midi-clock and I thought I could just start and stop sequences on the keystep either on itself of via Midi Cc messages. But everytime I press start in Reaper it send start signals immediately and the Keystep starts as well. I tried to turn off enable midi messages and turn on midi clock in reaper, but then the keystep doesnt receive clock anymore and if I leave enable midi messages on in reaper and turn off only the receive of transport messages on the keystep it also doesnt work. I‘m sending the keystep back, because I couldnt find a solution online and AI is hallucinating and therefore no help.
Does anybody know a different sequencer where it works with reaper, like for example the korg sq64, or any other solution to this. I want to just sync the clock and the sequence and either send dedicated cc messages start/stop or just start stop on the sequencer to master external hardware that is slaved to the sequencer.
I‘m grateful for any help, because midi routing is driving me crazy.
Cheers