Originally Posted by
awaflyer
I have the Nexus card and usually get the TSA precheck, especially when flying on Delta and American. Lately I haven't gotten it when flying on Alaska. I called Alaska customer care about another issue and asked about this. It turns out that if you are upgraded within 48 hours of your flight, which I have been the last few trips, then that counts as a "change of your ticket" which prevents using the TSA precheck.
Good to get upgraded...bad to have to go through the long line!
I am sorry you received this answer from AS. I can tell you with 100% certainty, that this is not the case.
With that said, almost all failures are due to name mismatch. In general, if you see anything other than first and last name on your boarding pass, you "may" have an issue.