Getting Inifinite RZero (both raw and Corrected)?

[ccrvlh]

After quite a while running the sensor (+24hrs) and correcting temp/humidity using the DHT22 I keep getting inf RZero and CorrectedRZero, while PPM (and correctedPPM) stays at 0.00.

Currently using a CCS811 that reads CO2 at about ~500ppm which seems ok.
If I throw a bit i light gas into the sensor, RZero drops to zero, and then rapidly rises up untill 100k and then infinite, while PPM moves slightly (like 0.1 or 0.5, something like that).

I've already corrected the getResistance formula on my local library, but was wondering if there was anything else I should be doing. Thanks.