Press and hold on the spam message then click “more”. Bottom right corner hit the arrow. Send that to 7726, you will receive a text to enter the number that spammed you and the report will be complete.
That is exactly the procedure I am using.
I was able to report the issue to Telus and they have forwarded the issue to their spam department, who will NOT contact me. Maybe they can replicate the problem and fix it, but I'm a pessimist.