another noob trying to tune the servo

STEPGEN_MAXVEL = 5

^ This needs to be 25% larger than this:

MAX_VELOCITY = 25.0

no luck, tried 25% larger and more , also tried increasing STEPGEN_MAXACCEL


MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 40
STEPGEN_MAXACCEL = 1500

Those changes are necessary but not sufficient...

Looks like you don't have the stepgen enabled

there is definitely something odd here, please look the attachment

Not really very odd, thats expected if the stepgen is not enabled

As allways you are completely right, the problem was that the 7i78 doenst have enable signals, so I had to use one of the 7i77 outputs:
net z-enable <= axis.2.amp-enable-out
net z-enable => hm2_5i25.0.7i77.0.0.output-00

but forgot to:
net z-enable => hm2_5i25.0.stepgen.00.enable