I no longer use Arch, but this wouldn’t have happened to me because I used vanilla Arch. On Manjaro it can happen at any moment that an AUR package silently depends on a new part of a dependency not implemented in the older versions. The AUR does not care to figure out which exact version dependencies are needed for a program, because you are expected to always have an up-to-date Arch system before installing. If the AUR cared about Manjaro compatibility they would need to mark every dependency with a minimum version number, but that’s a lot of effort and the AUR understandably doesn’t care about supporting Manjaro’s repos. If Manjaro stood up its own AUR this would no longer be a problem.
(Personally, I don’t think AUR packages are a good idea for system stability/security even on vanilla Arch, but it is understandable that people like them for their convenience.)