Bad DOMS right now, makes no sense?

Last big endurance ride 135 miles end February no issues, training program with endurance sessions, one interval session and one very hard 60 mile group ride every week. No issues.

Go riding real easy with an old friend Saturday, 65 miles has me in zone 1, for most of the ride, finished with an average heart rate of 102, about 4 hours on the bike and Sunday my legs hurt like hell, and still hurt today?

Makes no sense???

Anyways, I will stay off the bike until Wednesday, then do a few loosen up rides, doing Natural bridge GranFondo in VA coming Sunday, close to 100 miles.

Wish I understood this, but perhaps a sign of bad over-training?

This is normally the case with me, DOMS comes up for no apparent reason.

Thoughts, anyone?