Pre-Chat form has a feature that tries to match the information entered, with existing records. If no match found, a record will be created and Chat transcript is associated with that record.
For some reason, record creation is not working in our sandbox. I have tried the same functionality in my trailhead playground, It is working as expected and the record is getting created.
I have done all the troubleshooting, checked profile, FLS on the fields, Record types, etc..but no luck. However, finding the existing records and associating chat transcript is working fine. Am I missing anything?