Changing volume in audio mixdown

Hello! I am using Cubase LE AI Elements 7 and I have the following problem: When I play the audio mixdown in the player the volume keeps changing. The quiet parts get gradually louder and when the loud part hits it gets quieter(and it’s not a smooth transition either). When I listen to the whole song in Cubase it sounds ok, but when I export it the problem with the volume appears.
I am exporting at 44.100 kHz, 24 bit depth, .wav(Wave) file format. I have tried changing the file format but the problem persists. I am not using a compressor for my whole mix(only 3 drum tracks).
I really hope someone knows the fix to this problem, I have searched the internet and have found nothing.
Thanks in advance :slight_smile:

This issue is doing my head in. The mixed track simply sounds nothing like how it sounds in Cubase. Very disappointing.