Mounting a TV

Hey all,

Mounting a TV. I've mounted about 4 TVs so far no issues finding or drilling into studs. In my new apt I want a TV in the 2nd bedroom.

Im using a highly recommended stud finder called zircon hd55, using it set to deep scan mode.

Problem here is I find the studs once I start drilling drilling won't go through, probably hit metal? But not 100%.

I'm trying to learn how to know for sure and if there anyway I can get this TV mounted! It's a small room and I need to get rid of the TV stand.

P.s. it's a 55 inch TV that weighs 30.6 lbs.

but when I drilled into the wall I think I hit metal