Can't run experiment - code not validated
I am trying to run an Experiment in Google Analytics. I have my original page and variant. Everything is set up except for the last step, Experiment Code Validation. It says "No experiment code found." and "No Google Analytics tracking code found." but I know for a fact that both those codes are present, especially my GA tracking code. I have data coming into my Analytics every day and Google's Tag Assistant Plugin recognizes the code. I use GTM to add it. But this experiment won't run because it can't validate the codes. I tried running it anyway but I get no data.