Display issue when I lock my laptop

Hello,

so everytime I go for a lunch at work and before that I lock my laptop (Latitude 3420) so when I come back my resolution of my dual display (DELL U2419H) changes to a lower resulution, but the 2nd display (DELL U2419H) does not change... So the only way I have found how to fix it is to remove the HDMI cable and plug it back to my docking station (DELL Dock WD19S)!

Also I unplugging and plugging the cable from my display fixes the issue. This is getting annoying to do every day... Does anyone have a solution for this? I have already tried updating my laptops GPU driver and the driver of the docking station, but no luck. And also I have tried changing my display cables. Thanks for the help if anyone has faced this issue!

Best regards

Sami