I know the feeling. Both for the frustration of having an issue with a filament and running around circles like the OrcaSlicer bug.
Try tracing back whenever that happens.
For example, you have a reproducible bug. Store the project file away for reference (for the Arc bug).
Now, how did you start the project? Was it like with me, a project that was first created in Prusa Slicer and then moved to OrcaSlicer? Or created on a previous version of OrcaSlicer?
So, the first thing I’d do is export the STL from the slicer, create a fresh project and import it the STL (or if it’s your own design, simply start a new project and import a fresh export from your CAD software). This way you can get rid of any dirty setting that may be lingering in the project file. I know for certain that is definitely possible. STL is a binary model file, unlike 3mf that can store any arbitrary information.
Once.you have done that, verify the sliced gcode and check if the pesky gcode is still there, if it’s not, you have narrowed to the source of the Arc issue.
As for the filament not sticking, sometimes it can be really stupid (ask how I know). For example, I had a similar issue with a very specific filament (type, color and brand). But it had nothing to do with the filament. In that project specifically, I had a nozzle diameter defined as 1mm. I have no idea why that was like that. A fresh project may also help identify that there is some setting in the project creating issues.
Finally, I often get bed adhesion issues and usually boil down to either of these:
- improper temperature settings: Too high temperature can be a problem and if you’re printing slowly that is specially true as the filament remains cooking in the nozzle for a longer time. I only exaggerate filament temperature when printing very fast or with hardened steel nozzle that is a worse temperature conductor. Similarly, the bed temperature needs to be higher when printing hotter stuff, but that may not work well with PETG that doesn’t have a very high glass transition temperature.
- nozzle too close to the bed: Some filaments like to take a ride in the tip of the nozzle. So if the nozzle is too close to the bed it may grab the deposited filament. This can get worse depending on the type of the nozzle, like what I have (ruby tip). So form factor can play a role here. I’d swap to a different nozzle to see if there is a relation there as well.
- wet filament: That speaks for itself, make sure your filament is dry.
- Flow rate tuning. Sometimes the flow rate is just wrong. Which can be from bad extruder tuning (some filaments are more sensitive than others), improper filament settings, etc. OrcaSlicer has a flow rate calibration tool. I encourage you to use that. In fact, I’d go through all available calibration tools as much as possible.
In the end this is an annoying thing I beleive most of us encounter. The way to go (before blaming the filament) is to try to identify the cause, it usually not the filament, and developing a good debug procedure will save you time and frustration whenever you encounter an issue. Good luck.