I have worn FTL shirts for many years.
This batch was disappointing because they shrunk a lot after a couple of washes. We don't use hot water to wash cloths so that isn't the reason and I have been losing weight, not gaining of late. So it has to be the shirts themselves.
I am hoping I just got a bad batch of shirts and FTL isn't using poorer weaving techniques.
But I would advise you to maybe order your shirts one size larger than normal. If they don't shrink like these did you can always wash them in hotter water so they shrink down to your regular size but if they do shrink without being washed in hot water, they should still feel like they are the right size.