I’ve had helix since 2016 and have never experienced this before with many pedals that have come and gone and I’ve used inside the fx loop and I also checked it just in case and nothing wrong on my end.
Did you happen to try my suggestion but do it with low volume just in case!
Put a pedal into insert 1 and move it to parallel path, then take insert 2 and move it to pre (in front) and see if it does it for you?