@Lizzit right most likely this is the case, especially since it is hard for a system like Cloudron to correctly detect and fixup already made changes or package installations to fit its need for a stable update-able system. To maybe say this in advance, also after having installed Cloudron, it is not supported to install other things on the side, as it will eventually break on updates in our experience.
Note that Cloudron is aiming for reducing the technical complexity for selfhosting and reduce time to maintain it, which requires some more stricter control of the system as such and we have decided on that route, since with the affordability of virtual servers it is likely much easier to just get a fresh Ubuntu rather than trying to debug configurations on updates.