Hello!
Thank you for reporting this to us, and I'm sorry to read the silver boost doesn't appear to be working.
This isn't a known issue, however we can investigate. Are you perhaps able to provide a short video of you earning silver (finding it, selling things, completing a raid) so we can see how much you're earning? We can then discuss it with the AC Valhalla team to see if there's an issue.
Thank you!