I have this continuous problem. It seem that cargo trunk cover is too short for the distance between the fixation places. I draws attention of course only when putting thing into the trunk.
The view is that one side hangs lower only because the gripping mechanism catches the rim of the interior. Dealer measured trunk cover from another car and it seem that the problem is in the space of the interior but I have no ideas how coud the interior parts shift so much for the cover to become too short.

If anyone have some ideas about fixing this problem please let me know

Welcome

A picture showing the problem might help someone offer a solution

It 'should' be a simple fit of the cover and pull it out to the desired fixing point (I believe there are two. It soulds like your cover/mechanism has taken a knock and is compressed. Again a picture should help.  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

ill download a picture as soon as possible.

Had this with mine and dog guard was blamed by stealer. In the end they replaced the side panels and packed them with foam between the cover and inner wing. LR technical say it is a reaction to heat and cold and the panels eventually shrink. Even with the foam the same is happening again and won't be too long before the load cover starts falling into the boot again. Design issue that is not the load cover but the mounting points. Great for a 60 grand car!! 2x TDV6. SE and HSE. Both returned to sender with issues👀
TDV8 Sport HSE...... Gone. Loved it but it didn't love me!!
Now rolling in MY10 Fullfat TDV8 Vogue. Slammed it to go round corners🙈
Cruising daily #56 mph in a Volvo V8. 😱
Lots of other toys in the cupboard...😜

I had the same problem with mine.

Shoved a couple of erasers in one side.... Sorted

 2009 3.6 TDV8 HSE Santorini Black