Mute switch and lcd marks?

Hello everyone, i have an iphone 6 and i recently changed the screen. Just around 15 minutes ago, i was cleaning the screen with a cloth and applied a little pressure to remove all the dirt from it, and i noticed some marks on the left side of the screen (only when pressure is applied, not when i touch). The marks are very close to the volume button and mute switch.

My mute switch doesn’t work really well since i broke my phone for the first time (yes this is not my first screen replacement ahahahah) and when i mute the phone it just mutes and unmutes multiple times vibrating.

Here comes the curious thing: when i was applying pressure to my screen with the cloth, the phone vibrated and muted, as i probably triggered the mute switch by pressing on it with the screen.Now the mute switch works perfectly fine again!

I was wondering if there could be any relation with those marks i see, cause in other areas, if i apply pressure there is no mark at all.

Also if it’s not related to the mute switch thing what it could be

I’ll leave a picture to show the area where i see those marks

Thank you so much for reading and sorry for my english as it is not my native language :)