I have checked various forums concerning this issue and found that its not the first time it has occurred.
Bosch have issued various versions visible on github, the latest being 3.5.10 dated 1/2020
Version 3.5.3, 3.5.6, 3.5.7, 3.5.8 and 3.5.9 all included changes to calc_pressure.
Current version 3.5.10 also has seen several commits that change calc_pressure too.
Your distributed version of this library says its based on 3.5.5 so its old old old.
It seems evident that the very complex calc_pressure function has provided more than its fair share of problems over time.
So, like I said in earlier post, please update the library to latest stable version 3.5.9, let’s see if its more stable and gives a more accurate result.
I also suggest to include new function calls in Seeed_bme680 to provide for altitude compensation, calculate altitude and initiate recalibration.
Thanks
Bryn