Hi,
Same thing just happened to me. I renewed two certifications and the date updated as expected, but on the third one the expiration date remained the same and the button to take the assessment is still enabled.
Please ask your question in the Microsoft Certification forum using link below. There are support moderators over there that will respond to your question in 1 business day and can assist with fixing the expiration date:
https://trainingsupport.microsoft.com/en-us/newthread?threadtype=Questions&forum=mcp
Please click Accept Answer if above was helpful.
Thanks.
-TP