Occasional erroneous execution of correctly compiled code


I installed the ncs and Zephyr environment following mainly the guidelines from nordicsemi, a few changes were necessary to use Eclipse. The installation process at all was ok, I can modify and run examples, so I could start to work. On hardware side, I'm using nRF52840-DK.

Currently, I'm on the BLE stuff for maybe two days per week. During the last 4..6 weeks, I faced twice a quite strange behaviour, last time two days ago (Tue, 21st June): I can compile my code without an error, but when running it, it behaved different from what I saw before (e.g. wrong frame types or no AUX_ADV_IND frame after three correct ADV_EXT_IND frames etc.). My examples were running correctly before, and I used exactly the same code (new Git download). This behaviour I found for several of my examples, not only for one. It behaves this way for hours (I don't know exactly how long, because I stopped working after discovering this strange issue). One or two days later the same code runs again well, i.e. with the expected behaviour.

What happens there? I don't know if the problem is on BLE side or on Zephyr side, but could it happen that in these parts, which are more or less in a development stage, some update processes are not running as expected, i.e. update processes might cause such issues? This would point more to Zephyr, because the ncs installation is fixed, while west continuously updates Zephyr, when I understand the compilation process correctly. Anyway, it is strange - is there any explanation for such things?