Any advice with master rank rathalos?

Hi again guys...
Sorry to bother you again, but I'm absolutely frustrated with this.

Since the fight with Barioth I've tried to slow down a bit and try to farm for armors and weapons I like, but i cannot do anything with Rathalos.

I have some master rank rathalos investigations, set to 35 minutes.

I've done 7 tries, 5 of them failed because of time.

I literally spend most time in the mission pursuing him than fighting him, i'm not joking, the last time, the fight started at min 6, because of various things, first one, every fking time i get near rathalos he just goes to another area, I'm getting really frustrated with this, added to the fact that the map he is on, that i can't for the love of god orientate myself in, (is impossible to me, I've even gone into 2-3 expeditions without huinting any monster, just to explore the map and get familiar with the terrain, but i cannot do it) and that, when I'm fighting him, he's near 90% time flying, is making me fail the quest,

I've tried spamming flashbangs everytime he is in the air, (I've used everyone i have, in fact i have to get more flashbugs), focusing the wings, using the terrain, using the claw to try and make him down, slaming him vs walls, even shot him with the sling to try and make him be near the ground, but i just can't.

I really dont understand, I've done tigrex fight and brachydios fight 1st try, just carted one time vs braqui because its my first time seeing him and i dont know the moveset.

But i try rathalos and I'm helpless, cant barely hit one or two attacks and then i have to chase him and try to dodge like 10 thousand fking fireballs.

Also, wtf is going on with stuns? Maybe its just that I'm getting hit more than normally, but im being stunned like, a lot, a lot lot.

I dont know, maybe world just isn't for me? It's the 2nd time a monster i absolutely love in other titles of the franchise is giving me the worst nightmares ever. First barioth which gave me a really hard time, but when i learned that breaking his parts is super usefull, it got somehow manageable, but with this guy i don't see a way around him.

Anyway, do you, again, have some advice? There is some mechanic I'm not getting?

It is possible that i just got burnout but omg, I have not experienced this frustation in wilds with the arch tempered enemies or rise even with Crimson valstrax or his normal version the first time(absolutely love every bit of that fight),malzeno and his primordial version, amatsu and those high level ancient dragons.

Thanks in advance and sorry for the rant.