It makes sense. Many SSG are still needing to complete their ALC-CC, and they should have it done before being considered for SFC. The backlog has to be cleaned up, and SGTs, particularly the Non-promotable guys, are the first ones that need to be shuffled to the back.
That doesnt mean you can't remain competitive for SSG. Keep working to build your value as an NCO, and you will accumulate points. ALC is worth 90 points at minimum, and there's no denying this is a substantial portion of your points, but it isnt everything. Dont forget the 710 points that are not tied to NCOES. Once you work on getting promoted without NCOES (it can be done), then you will be higher on the OML and get slotted sooner.
Stay motivated! It will work out, just make sure you take control of your progression as much as possible. Get other Military Education if possible. You already are taking control of your education, and you deserve to be commended for it. Congratulations!
As Major Sheridan suggested, and you acknowledged, career changes might be your best route.
Dont count on learning anything at ALC that helps you train or lead your guys better, either.
Positions held are not used for OML. Grade, TIG, TIS, and promotion status are. This is not new.