Just for kicks......disconnect the vacuum line and plug both ends, and set the petcock to prime and see if anything changes.

It could be that something is stuck in the float needle/seat and it allows a small amount of fuel to flow as the bike sits, and the fuel level is too high in the float bowl after sitting overnight.  The vacuum petcock does shut off the fuel flow - but there is fuel in the line that could be slowly filling up the float bowl as the bike sits.  As you continue to ride you may be lowering the fuel level and the overly rich issue goes away.

Gummy/clogged jets cause the bike to be lean....so that most likely is not a problem.  Even now and then somebody gets a float that fails and allows fuel to enter the float....and the heavy float allows too high of a float level.

If the symptoms all started just after you did that work....then I would look there first.  Perhaps it is not seating properly.

Since it's an idle issue, the TEV is a good guess.
Every once in a while we get someone with a weird issue that goes away.
But easiest cure is to drain the gas and replace.
Throw in a ounce of seafoam and hope for the best.

Idle on the sidestand is death.

It won't oil the high end of the cam.
Dave has pictures,

Ok, I tried something else. When I disconnect the vacuum hose on the carb and plug the nipple, take the end of the hose in my mouth and suck a vacuum on it, it idles fine.
I try and put a new piece of hose on it and see then.
But it seems like the vacuum from the carb is not strong enough.

I put a new petcock in there about four years ago. Just to prevent those failures. Could it be already defective?