My Zero started having first layer issues last night. I thought it was caused by switching to red Rapid PLA+ when I’d been using black, so I had a few failed prints trying all of the first layer tricks I know, and even had a couple of minor cases of the nozzle dragging across the build plate (which should have been a clue) but the problem persisted when I switched back to the black filament. While changing nozzles I noticed the Eddy sensor was very loose. Tightening the mounting screws and running Eddy calibration from the front panel seems to have fixed the problem. Maybe keep that in mind if you have mystery first layer problems, or the next time you have the cover off the tool head, snug down the Eddy sensor mounting screws.
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@Liberty4Ever my Eddy sensor has had a few issues, the loose screws was one, the other is the plastic seems to not be as heat resistant as one might hope. My sensor housing actually broke in the upper right corner where that top screw mounts it to the tool head, and the housing warped a bit.
Probably me, but the little gray clip that connects and locks the sensor harness down, that flexible circuit style harness, had worked it’s way loose. This was either when the sensor screws were loose and it was shifting around, or me fixing and adjusting it, not much space to work in big hands and old eyes 
Not sure if you had any of those other issues, if you want to check I placed some photos showing the cracked housing and warping Maintenance guide or recommendations for a Sovol Zero? - #3 by MikeHides
Cheers,
-Mike