Melting Black Seal Rubber

I was so confused when I start to find some sticky dark lines on the edges of my MacBook, shock to realised it's from the black seal rubber around it's screen. I guess it starts to melt of...

So here I am looking forward to find some useful answers...

It's an MacBook Air purchased around late nov 2019 i believe.

I was very careful with it from the start, it was the most valuable thing i bough It looks new and everything works fine till I noticed that problem...

Because it's weight... I do have an other MacBook air that i use more often & travel everywhere. I have to mention that without using it every day, I'm aware of shutting it down before i put down the screen. Never felt it gets too hot or hear any notable overworking strange noises... therefor, other than crazy hot summer weather, i couldn't think of any reason for this problem.

By touch, that rubber is hard but fragile now, some little parts still had a bit of stickiness and the screen top area (near camera) missed some rubber sections... also is the most damaged area so far. did't find any more rubber drop-offs lately...

I try to ask people who had same MacBook, but not able to fine any with the exact problem... the internet seems to find the common problem is usually caused by screen reparation. only few people with the same issue mostly mentions Apple recommend them to change their whole screen (with the price not much could agree), didn't provide any specific replacement for the rubber it self.

I never did any reparation for my mac and with it's condition I don't think I'll pay that much to replace it's screen. But also afraid to bring it to any shop...

I'll like to ask if anyone know what cause the rubber to melt of like that ?

Does Apple provide any specific replacement for the rubber part nowadays?

Is there better way to fix my this or should i just ignore this problem... ?