The QR is brand new. It is not nailed to the floor.No one here was there when you installed it so I'll make some guesses and some can be wrong because I was not there.
I can see a bunch of possible issues.
You did remove all the 1/4 round before installing right?
If it was installed after the floor went in the nails needed to be into the baseboard not the flooring, one nail in the flooring and it can buckel.
Around that fire place there should have been enough gap to install a transition strip.
Where the flooring meets the tile all I see is lots of trash left on the floor and no room for a Tee transition strip.
When I get stuck with installing laminate you do not simple set in place and move on, you need to work it up and down getting closer to the subfloor each time, once it's flat I tap over it with a white mallet to make sure it's locked in place.
If there's any gap stop and fix it!
I'm seeing tools on the floor that scare me, what's the hammer and what looks like a Dremel tool for?
That's exactly the problem. Any idea what to do about under the door jambs?In the second picture it sure looks like the metal stip was screwed right through the flooring which is a huge no no!
Read the directions right on the package the stip came in.
Metal piece should have been installed and the flooring ran up to it leaving a gap from the flooring to the strip.
I pulled off some door casings near where the buckling was the worst. They all had proper spacing between the laminate and studs. I have no clue what the problem is.Maybe by pulling off the casing a little at the bottom. Then you can get in behind the casing to fish the pieces out---if they are there. If it was already undercut then the pieces should have been removed. Or maybe the flooring is now tight to the stud behind, but you'll be able to see that if you pull the casing out a bit.
B is very short, just a few feet.That's a lot of flooring you have there. What is the TOTAL length in direction A and in direction B ? You might need some expansion joints at intermediate locations.