Iphone 8 vibration weak on calls, notifications, etc

After a recent IOS update my phone's volume became too low and vibration weak. At first i thought it was caused by the update but i then found out the bottom speaker was no longer working. Before doing anything i restored the phone and removed apps i don't use. Since that made no change i decided to replace the loud speaker. As the phone is no longer on warranty i replaced it myself. Since i was going to open the phone anyway i replaced the ear speaker as well. I now have normal volume on speaker and ringer but the vibrations remain weak.

I have searched online for ways to increase the vibration level but all i can find are steps to create a new vibration pattern, which i have, still no change. The odd thing is when i select a different vibration pattern or create a new one, the vibration can be felt when selecting either of them, but when i get a call or notification the vibration is weak. When i move the mute/ringer button to silent all i get is a very weak pulse. I have tried editing the vibration on all available options in Sounds & Haptics/Sounds And Vibration Patterns. As i wrote above, the vibrations appear normal when making changes on this settings section, but they go back to weak when operating the phone normally.

Not sure where the vibration engine is located (thought it was part of the loud speaker), but regardless, i think if it was bad it would also vibrate weak when changing vibration patterns in the settings app. Would restore the phone again now that i changed the loud speaker, but that did nothing before. Any suggestions aside from replacing the phone?