Build APK for a modified ODK Zebra Printer Driver

What is the problem? Please be detailed.
I have a modified ODK zebra printer driver in android studio. When I run and deploy the app directly to my tablet, it installs and prints the barcode labels correctly. This is not the case when I build the apk through Build menu >> Build Bundle/APKS >> APKs or through Build menu >> Generate signed Bundle/ APK >> APK.
I try to install the apk generated and get the error 'Application not available'.

What ODK tool and version are you using? And on what device and operating system version?
ODK collect v1.18.2
ODK Sensors
What steps can we take to reproduce the problem?
Installing on different devices
What you have you tried to fix the problem?

Anything else we should know or have? If you have a test form or screenshots or logs, attach here.
These steps worked fine last year. Trouble started when I formatted one tablet and trying to re-install the odk tools

Thank you,