I was in the same boat; I'd completed the 1250 SQPs to keep my gifted Gold, and eventually made ~2600 SQPs so therefore should have been Silver until 12/31/26.

After getting on the text chat ((855) 728-3555) they (finally) referred my case to someone and after a couple of days I got my Silver back (and unless it's yet another Spirit IT glitch, for longer than the airline may even exist).