If the fitting was recently pressed (15-20 minutes) prior to pressurization, it is possible the bubbles are a result of trapped air in the double crimp area that can leak out over time, and IS NOT a fitting leak. This is more likely to occur on smaller fittings.
Since the joint is a permanent one, if a fitting is leaking after this period there is not much that can be done to address it. It’s best to remove the affected fitting and replace with a new one.
If fitting is to be returned for analysis, please ensure that there is AT LEAST 3 inches of tube on each end of the fitting so it can be analyzed, and leak cause determined. Without sufficient tubing, fitting can’t be tested and leak confirmed.