So you may want to try letting the flaky cards start with defaults and then after a time period send it API adjustments. I do this by adding a simple script to my start up process. This requires that you enable the API interface mode as well.
Here's fixcg script for example.
sleep 20
echo -n "gpuvddc|2,1.04" | nc 127.0.0.1 4028 >/dev/null
echo -n "gpumem|2,250" | nc 127.0.0.1 4028 >/dev/null
echo -n "gpuengine|2,760" | nc 127.0.0.1 4028 >/dev/null
and the settings I added to my conf file to enable the API.
"api-allow" : "W:127.0.0.1",
"api-port" : "4028",
Just throwing this out there in case it helps anyone with similar weirdness.