Not able to create an A/B test reports with Subject line test varient
Hello All,
Recently, I did come across that we can't able to create an Email performance report under the A/B test program with Subject line test variant.
So, we did analyzed this and found what causing this issue in Marketo. When we clone any existing A/B test setup, then the email performance report won't be available(can't able to select test variants) for that program, until remove the existing setup and re-built it again. So, if anybody clone the A/B test setup further, then please remove the existing setup(Click=> Remove A/B test option in control panel) and built it newly. So, that the Email performance report will be available for the emails that used on the program.

Solution/Fix:
Please remove the existing A/B test setup on cloned programs and re-create the same for avoiding these kind of issues.
Also, raised a ticket with Marketo support to confirm whether it is an expected behavior or not. Will keep you posted the updates
Thanks,
Kumaresh