unfortunately the new "core_upgrade" wallet i've migrated to seems buggy as hell.. once it found a block it forked off the main chain and got stuck on that (found) block.
I'll go back to the stoneage-codebase wallet now, wait a lifetime for the resync (approx 3 days), then process the payouts and FINALLY close the pool for this coin, i'm done with it.
Bad news, I like suprnova. Maybe devs can help? Or let's go to zpool, we need to spread the hashrate.