Some apps do not adapt to the system wide language settings

Themble

I have got four languages installed because I want to be able to switch between them every now and then. However, not all apps follow my settings instantly. When I e.g. switch from language 1 to English and back again, one app sticks to English. I have no individual language set for any app. The support site of the app says that the app's language depends on the global settings of the phone. But that doesn't seem to be the case. Even a reboot or deletion of the app's cache memory don't help.
Now I have realized that another app is stuck in language 2 without any obvious reason. Can anybody help?

Bobby159

Hi, same here.. installed eSpeak NG and google Speech Recognition & Synthesis for testing. After that, the garmin app starts for about half a second in german and switches then to english. Systemlanguage is german. Tried to install english as second and first language, rebooted, switched again, deleted the english language (one one language -> german), rebooted again, app still english.
No Play store or Services installed.

Garmin app:
The garmin app uses systemwide language only, so no option to switch in "apps language" menu,
Tried also clearing the cache, uninstall / reinstall, deleting remains of the installation after uninstalling.
nothing worked yet... anyone any idea?