Hi Ike@ACE
I think it could be helpful the following points so check/clarify:
1.) Is the issue based on the specific thingmark print. Scale, print quality etc. - is the issue reproducible with other project (possible simplest project) with the same or different thingmark
2.) location , possible light conditions , environment
3.) using the same thingmark on mobile device , possibly similar configuration and check of IOS or Android have the same problem ( just as reference to compare)
4.) check the log. file if there are some errors or warning - when you scan the thingmark. -> log file for specific device type according : https://www.ptc.com/en/support/article/CS283816
