@jsulm I have tried that and this didn't work. Background services can and will be suspended as soon as there is another foreground activity/service, which seems more important to the OS. This option was also discussed in the thread I linked above. A foreground service on the other hand stays active even if the bound activity is in background.
Please also note, that I target Android 8, which imposes even stricter policies on background services, as described here.