When I set focus to infinity, picuture is not sharp. If I choose AF and touch to focus at distance, picutre is sharp.

Is this standard Osmo+ issue?

I don't know if it's a standard issue but it is a issue with mine as well. Good luck trying to get a reasonable response from DJI.

Infinity Focus causes confusion because of it's name. It doesn't lock focus on 'Infinty' but at some hyper-focal distance to give you a reasonable range of focus for 'point and shoot' WIDE ANGLE capture.
As you have found if you want to get pin sharp distant focus, use the tap to focus method instead.

Thanks Dave, That makes sense.
What about AF mode though. Will that do any auto focusing on its own, or will stay with wherever I have tapped the focus at?
I know there is  a setting for  focus when the gimbal stops moving also. Is that more of an autofocus but only goes into effect when the gimbal is still?

Lenny, the only 'autofocus' the Osmo+ does is at the end of a zoom move. I can understand users being confused because the camera will refocus if you change viewpoint when it's in preview mode (you will hear the little beep as it does so).
I find the tap to focus suits my shooting style. I can frame a shot, tap and lock focus, then know it will stay locked if I re frame.
cheers