Slow Rendering on some Android devices

Hey guys, I’m still relatively new to ionic and angular, having originally been a web developer. I finished my app, tested it, and submitted it to the Google Play store. The pre-launch report came back showing that the app did not perform as well on some lower end devices as shown below.

I wanted to get some advice on what I could do to improve this. Any help is appreciated. Thanks.

Additional info:
i) My app is an offline reading course that contains the main page, a chapter menu page, nine chapter pages (with the reading content), and a settings page.
ii) In the app.module.ts I have enabled PreloadAllModules.
iii) The app.component.ts only imports the capacitor splash screen plugin and hides the Splashscreen after 2 seconds.
iv) The only additional modules I use are Ionic storage in the app setting services to store a font size setting and ngx pinch zoom.
v) I was having a splash screen resize issue, so I instead used a custom Splashscreen vector asset in Android Studio.
vi) I’ve tried to use source map explorer but had no luck generating the tree visualization in the browser.

Seems you need to optimize your code. go through each feature and look at the places that need refactoring and optimization. Look at each function, make sure your following angular guidelines…etc…