I just set up some basic scoring in Marketo and noticed that SFDC is changing my behavior score back to "0" during the sync process. I believe this is because of how I have the fields configured/mapped but not sure how to best troubleshoot. Here is a screenshot of what I see in salesforce. As you can see below, the score changes in marketo and then SFDC reduces the score back to 0.
The standard lead score field appears to be still maintaining the total score (23) but the behavior specific score is going back to 0. I assume it's because this is a custom field I created and maybe I set-it up wrong.
It might be that you don't have write access on the SFDC field. So SFDC restores it back to 0. It could also be the contact is owned by an inactive owner or there's a validation error. In both cases changes are not kept in SFDC. Or maybe there's a formula for this SFDC field, which says the value must be 0?
More questions to try and answer your question.
Was the field "behavior score" created in Salesforce?
Following on Diederik Martens thought, does the sync user for Marketo to connect with SFDC have full read write access to all fields?
Yes, the field behavior score was created in SFDC. The marketo user does have full read write access. I am guessing maybe the field type I set-up (number) is not correct? I will probably log a ticket with support but thought maybe there was an obvious fix.