Rekordbox freeze/crash related to graphics or GPU (compability?)

0) Have you read the "READ ME FIRST" thread in its entirety AND TRIED THE SOLUTIONS THERE before posting: Yes, I swear it!
1) Operating System: Windows 10
2) OS Type: 64bit
3) rekordbox version: 5.4.3 and 5.4.2
4) Using LINK: No
8) Is rekordbox crashing at all: Yes
8a) If crashing, is it resulting in: an error message OR a crash log OR both (DO NOT POST YOUR CRASH LOG UNLESS REQUESTED!) No it's not giving me anyting
9) Are you able to repeat / reproduce the problem: Yes
9a) If yes, can you do it consistently: Yes
10) Does the problem occur with one specific song: No

11) Any other notes regarding your setup only:
I use a DDJ-SB2 connected to a PC.

12) Provide as much detail of the issue here:

Rekordbox freezez when i start mixing tracks, to be precise: when it about to show the waveforms. The whole area with the tracks/channels/waveforms becomes black/grey. Program freeze.
Before i press play the menues work, analyzing works etc. The buttons on the DDJ-SB2 still works(i.e i can play and pause the music despite rekordbox being frozen)

This problem occured when i switched my Radeon HD5830 to a Radeon R9 270x. I used DDU and AMD's cleanup utility to purge old drivers. New card R9 270x work flawlessly in all other applications i've tried (a handful of them, taxing applications, mostly games).
The only problem is with rekordbox. I tried older drivers, didn't work. Tried uninstalling rekordbox+ deleting all databases: didn't work. Tried the older verison of rekordbox: didn't work.
I tried ditching the AMD software too, and just using the drivers, didn't work. I tried AMD second newest drivers, didn't work either.
So, because I can apparently run most(all i've tried) other applications, but not rekordbox, it seems like the problem lies with rekordbox somehow? Otherwise I would've though the pronblem lied with a faulty GPU/drivers.

I'm a bit stuck here. Help is appreciated.

My best regards