2005 turbo territory btr won’t go into 4 th gear .

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Hi , have a healthy turbo 2005 Territory (460 rwhp )  . We’ll was Na now Fg turbo . 
 

This problem has been coming on over the last week or so . First noticed it when I was boosting of in 1 st . It would just hit the limiter and not change unless I backed off my right foot a tad .

Today , while coming up on holidays, over took a camper van and it just smacked the limiter and after safely getting back in the LH lane . It wouldn’t go into 4 th or convertor  wouldn’t lockup  . Would go 1 st, 2 Nd , 3 rd at conservative throttle but not change to 4 th . But trump throttle would smack the rev limiter and the taco couldn’t keep up to the revs that was happening. 
 

Have reset to factory setting and through forscan ( no error codes came up Eg solenoid ) I reset the box but still the same .

So have I lunched my btr or is it a 4 th gear solenoid problem or is the box just down on fluid ( I serviced it 6 weeks ago with oil coming out of the fill point at about 50 deg c ) ? Don’t have any tool to check as I’m on holidays. 
 

Any help would be greatly appreciated? 
regards Graham.