I am pretty sure that you are doing something wrong, It works without problems on my MiSTer FPGA. I just played to level 3. Make sure you don't have any custom kernels like JiffyDOS enabled.
Update: Disabling GeoRAM and REU fixed my issue.
On real machines, you could have REU and a cartridge game on same time?It's correct that with REU or Georam enabled then CRT game won't works
