You can contact support@xertonline.com and ask them to take a look at your data and adjust your starting values. Xert Support can best advise you on what’s triggering the difference.
If’ you’d like more feedback from the community, post your XPMC chart set to 3 months or YTD.
That will give us a better idea where you’re at and perhaps explain the gap between values.
It’s best to learn what’s different about Xert versus the traditional approach. For example, how TP is derived versus FTP and why XSS is not equal to TSS.
Lots of newbie tips are posted here –
Onboarding steps for Xert trial users and newbies - General - Xert Community Forum (xertonline.com)