Gen 6 Gear Shift Issues - Not Shifting After Sitting Few Days

[AZ_Supra_Girl]

My Gen 6 GT has a strange gear shifting problem that only plays up when it's not been driven for a couple of days and when engine is cold.

If I drive it a distance, the next day it shifts OK. If I drive it daily it's OK but if it's sat for 2 days or longer it won't go into gear at all when cold and hits a wall. After about 15 mins of trying I can usually get it to move into gear and once it gets going after initially being stiff to shift for a mile or so it's normal again.

Clutch seems fine and gears seem normal and smooth if driven daily and not sat for anytime.

Dosn't grind at all.

Recent gear oil change didn't help, so it's something else.

Does anyone know what this problem might be, or has anyone else had this issue?

Need advice FAST.

Never had a problem like this before in any of my Celicas.