In my experience pork tenderloin is too lean to smoke low and slow. It just dries it out. Also, 190 is very over cooked
I would cook it much hotter it and take it to no more than 145 IT.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle