Samoban

Take out your filters, turn off the spa from disconnect subpanel, wait 30 seconds, leave filters out, turn spa back on. Keep filters out for 20 minutes and see what happens. Sounds like a flow issue from the filters themselves.

Try removing the filters, turning off the spa from the subpanel (disconnect) and turning the spa back on. A lot of the times the Hot Springs series acts up is simply just a circulation issue, and it seems to me like your filters could be the cause.