Tap automation most often fails on Samsung phones because of three One UI settings, not because of the automation app.
1. Battery optimization
Go to Settings → Battery → Background usage limits → Never sleeping apps, and add the automation app. Samsung's aggressive battery management can pause a tap script mid-run, which looks like the app "stopped working".
2. Display timeout
Settings → Display → Screen timeout. Set it long enough for the full run. If the screen turns off mid-script, the taps stop even when the app is "allowed".
3. Accessibility permission
Settings → Accessibility → Installed apps → the automation app → enable the service. A no-root auto clicker needs this permission to send taps; it should only perform gestures you configured and started.
An app I built for this
Phone Operator is a no-root Android tap and swipe automation app: single-point taps, double taps, swipes, delays, loops and reusable scripts. Free: unlimited single-point tapping. Pro: one-time purchase for advanced scripts. Rewarded ads can temporarily unlock Pro. It uses the Accessibility Service only for user-configured gestures and does not read, store or upload screen content. I am the developer of Phone Operator; menu names can vary by One UI version.
Settings paths are based on common One UI versions; check your device's current menu names.