Hi Modelt,
The Speed sensor appears to be a common problem on CFMOTO, not just on your Z Force but across the whole range. I have been getting the same issue since 2018 model year. It matters not how many times you change or renew the speed sensor the problem remains. It matters not if you set the gap between the senor and the reluctor ring to extreme accuracy the problem remains.
The issue fluctuates between being an intermittent fault to a permanent fault, if its intermittent starting and moving off wipes the fault form the ECU and knocks off the dash warning light. If it remains a permanent fault, then you have to wipe it from the ECU with the diag scanner.
From my experience the fault seems to appear if you key on the ignition in the garage and do not move off, i.e. the vehicle is rocked slightly back and forth without moving off. This seems to confuse the ECU i.e. “Am I moving or Not” so because it cannot figure out what’s happening i.e. am I moving or not, it defaults to safety mode and triggers a fault.
Just one of those little niggles with CFMOTO that one gets use to!!!
GMSAHFR