Regression in APK size when updating bundletool to latest version

We have an app that is mostly used in rural areas. We have a CI piepline in place to build apk from bundletool. We've been using v1.8.1 since a long time. Recently we thought to update it in an attempt to see if we can get any size savings from it. We noticed that apk size increases when updating bundletool to latest version.

Create release apk/aab from different bundletool version and use any apk analyser tool to check the difference.
This seems to be a regression. Is this expected that on updating bt version, apk size is impacted.