Yea don't worry about it.
On my 1998 car, same thing happened, but more pressing issue.
At a particular point got a test at 50% of limit specifically for NoX.
2 years later only did cold sit 10miles to test center, was at 90% of limit,
2 years later did 30miles highway before test with a couple pulls, at 50% of limit
2 years later did cold sit to 10miles to test center was at 85% of limit.
Your truck, even on your "bad" test is still under 25% of the limit so you're fine
