This place says it’s malfunctioning equipment -
https://www.kiro7.com/news/local/viral-eruption-threat-americas-deadliest-volcano-mount-rainier-not-accurate-pnsn-says/6SLJLI6YGRCPRLR3BWJVRAASJU/
A whole thread just melted away. I went to the PNWS site after reading this article and didn’t see any activity to correspond to the claims.