Hi,
First, please download ASICap from our website to make a test:
https://astronomy-imaging-camera.com/software/ZWO_ASICAP_WIN.exe
Adjust the settings to the same as ASCOM you used. If it works fine, I think it should be a software issue. if not, maybe it is a hardware issue.
If it is software issue, please reinstall the ASCOM and ASCOM driver, Or test it with other application, like MaxIM DL.
If it is hardware issue, please send an email to our support email. Tell him your problem. we will help you make a deeply check.
Thanks
Chad