I'm using Hyros, Google/UTM tags and Facebook to track my sales and make choices as to what ads to kill/scale.

I am having Hyros & Facebook miss sales but they are being tracked by UTMs. So in this case, who do I trust?

I thought a UTM tag works by having a person click on a link with x utm attached and if they go all the way through to the thank you page and the utm remains, then it gets reported back. Can anything remove the tag from the persons browser? I don't know if ad blockers remove UTM tags? I know for a fact it can't be added, so I have no idea how FB and especially Hyros is missing those sales, but the UTM is still working. Maybe I don't understand this properly?

I'd appreciate some input! Thank you!