i have the same issue too i suspect the default intensity of the miner is either too high or the miner itself is unstable making the entire system unstable & causing high ping'd submitted shares,
Amd or Nvidia? Whats the specs on the rig. Wich pool. Are you dual mining with zil? Wich version of the spminer?. Whats your launch config? Whats the corclock, memory clock and tdp of your cards? Driver version?
-AMD,7 old Gen 1 & 2 GCN cards
-i hopped on all vertcoin pools same result
-i'm not dual mining
-i tried all spminer releases same result
-my rig (an 1150 platform) can mine Primecoin & Turtlecoin just fine,two of the hottest most stressful algos out there
-as i said VerthashMiner works fine too
-the Driver is 18.6.1
just using the basic ....SPMiner -o stratum+tcp://xxxxx -u xxxxxx -p x --verthash-data verthash.dat --all-cl-devices