Same issue.
MacOS Monterey 12.6
Chrome Version 107.0.5304.110 (Official Build) (arm64)
Local 6.4.3+6116
I have no /Local/ folder under /Library/Application Support/ so I can’t try deleting the certs folder as I don’t know where it is.
Deleting the cert in keychain and recreating doesn’t fix the issue.
SSL loads fine in Firefox, Safari and Brave.
EDIT: I was looking at the wrong /Library/Application Support/. Found the correct one and @austinwendt’s suggestion worked to allow opening sites in Chrome in unsafe mode (previously that option wasn’t available).
The only thing I noticed different was that when going into Keychain Access the cert was already trusted. This was on a site that I has previously trusted through Keychain Access, but had deleted the cert (@austinwendt’s step 3).
So I’m able to use Chrome now, but it does require unsafe mode.
EDIT (again): Turns out the cert that was already trusted in Keychain Access must have been the original. I’m not sure why it’s still showing up after deleting the folder. But I noticed Keychain Access refreshed after a bit and another cert with the same name was there and not trusted. After trusting the new cert the site now loads in Chrome normally (no longer in unsafe mode).