Details:
98 Accord V6 Coupe
Issue with 3rd gear.

Front tires lifted and free from pavement:
Shifting into 3rd gear is fine. With car still lifted, I apply some brake to simulate driving resistance. Car will not shift into 3rd gear. RPM's rev and speed drops to 0 mph.

Driving test:
Car will not up shift into 3rd gear nor will it down shift into 3rd gear. Gentle acceleration always.

Car will shift into 3rd gear but only after I am cruising in 4th gear and move the shift selector into D3. Down shifting is a little hesitant but not jerking. With the shift selector in D3, transmission pulls good and holds. Moving the shift selector into D4 still holds the 3rd gear until speed is increased and automatically shifts into 4th gear.

What to do?
I have tested the 3rd clutch section of the shop manual. All checks are good - ECU and 3rd clutch switch.

Any ideas? I think I can show that the transmission is ok (at least I hope). All up shifts and down shifts are fine, except 3rd gear of course.

Thank you for your time.

Dennis