Is foundation repair necessary?

We’ve only had our house for a week and found a hairline crack in the foundation when pulling up carpet. The crack runs across the corner of a bedroom and also shows in the brick outside (small enough that we hadn’t noticed it before).

We’re planning to tile that room, so we had two foundation companies come out to check it. Their measurements looked different at first, but once I accounted for flooring height changes (laminate over tile, laminate over slab, and bare concrete where we’re renovating), the numbers lined up.

From what I’ve read, the general guideline is +/- 0.5” per 10 ft (about 2” across a 20 ft slab). Based on the surveys, our 1,300 sq ft house seems to fall within that range.

I’m planning to get a structural engineer’s opinion, but I’d like to hear from anyone with experience:

Does this sound like something that needs repairs? Or could it just be that it was never perfectly level to begin with? The house was built in 1983 if that matters

Should we worry about tile cracking if we leave it alone?

Or is the foundation movement minor enough that lifting could do more harm than good (like breaking plumbing)? We've already had to fix our sewer line outside the house because it was broken in several places. The sewer pipe is schedule 20 so I'm worried it would crack under the slab if we did foundation repairs.