No more mining on GTX 1650 4GB?

Hey out there,

today I'm figuring an issue with my Nvidia GTX 1650 4GB DDR5. I'm using trex miner for several time, but today it's doesn't start mining. It shows up a failure 'can't find nonce with device [ID=0, GPU=0], cuda exception in [ProgPOW::ProgPOW::initEpoch, 3..], out of memory Warn: WATCHDOG:T-Rex does not exist anymore, restarting..' I'm a bit confused it that as the DAG size is 3,25 GB, so lower than the card has. But I can remember it shows up the free ram space after initializing before and it was low (just about 30-60 MB, I guess).

After having trouble with trex I downloaded gminer and spotted the same issue. So here my question: Am I not able to mine Ravencoin on my GTX 1650 4GB anymore? Is there a possibility to get it work again as the DAG size is still lower than VRAM?

Some additional info, my GTX 1650 is not used for display. It's undervolted and overclocked via msi afterburner to +120,+450,+64 (clock, ram, power limit). It's plugged in a riser and just powered by molex (worked fine for several months..)

So any advice is very welcome!