Stiff Gear changes, possible cause?

April this year i purchased a 2011 Focus Titanium 1.6TI-VCT MK3 with 63090m, its now on 68500+m, absolutely wonderful thing to drive, now a couple weeks back on the way home from work at 6:30am it was fairly chilly but not cold. Coming to a red light ive pulling out in 3rd in to N, its gone amber and i couldn't get into the 1st, i repeatedly tried to get it in gear and with some serious force 3rd attempt it went in but it required really heavy force to do so. going down a hill i decided to test this again, ive pulled it out of 4th and tried to get into 1st (clutch is still depressed, break was in use) and it wouldn't go in smoothly unless i selected gears like a sequential gearbox, so i went down into 3rd, it was stiff, then 2nd about the same and then 1st seemed way smoother then going from 3rd or 4th to 1st 

when this happens which actually yesterday (27-08-17) on the way to work at 5am it happened again 1st is the worst, then 2nd is stiff and 3rd is worse than 2nd and not as bad as 1st , 4th not so much and then 5th slides in lovely, sliding out of gears to N seems to be normal, its going from N to 1st or passing through N as changing gears seems to be the issue

when the car is off the gears slide as they should do when i first Purchased the car its only when the car is running

now here is another annoying bit, i thought id need a transmission fluid change or could be the master or slave cylinders (which i know im covered under the warranty for) i ring them up and they recommend i take it to a garage that they deal with frequently, a Halfords Autocentre, right okay i get it booked in for 25th, drop car off around 1:30 (and at this time im only 25, i passed my test in january my knowledge of cars isnt that great and this is my 2nd car) i explain my issues to lad at desk as above in great detail as i can and he says ''yeah sounds to me like transmission, when oil is cold it contracts and when the engine is warming it up it expands so it could just need a top up, (i figured he might be right as when the car gets going and warms up the problem seems to dissapear) says what happens is i pay for diagnosis and they check for problems (i aint ***** stupid, surely if i explain my problem, for example i have a flat Tyre, they will repair or replace it and not pay for a diagnosis???) so i kinda felt like i had no choice, so i ask will it be done by 5pm? lad says we only need a couple of hours, so i drop keys and disappear, 5pm comes no phone call and i ring them and ask whats going on and get told the mechanic has been on the car for a while and hasn't been able to find a cause to my problem, but hopefully he be able to in the next 30 mins and id get a call, it was 5:55pm i noticed i hadn't gotten anything back and ring again, and i get told the mechanic cant find the cause, they are trying to get hold of the warranty to authorise work on the car which is alot of time and money (money i dont have, time im not fussed about) he says they think is something to do with H selector? have no idea what that is, i request to pick up the car but cant pick it up until the morning the next day, my suspicions is they had that planned as i didn't even get a phone call back to get updated about the ''diagnosis'' so morning comes and i pick up the car, the mechanics says they've had another look that morning and cant find the cause, he confirms its stiff in the gears i have mentioned, he has confirm Clutch good for 100,000m at least, then he said as they aint equipped, i would have to take it to a specialist to open it up and see what the cause is, on the plus side i didn't get charged this at all

im wondering has anyone experienced the same problem with the Focus and if so what was the cause? and is there anything i can do do check myself without voiding my warranty if not ill leave it to the professionals