Fairphone 3 animations are slower than on a FP2

/e/ version:0.92020042851613
Device model:Fairphone 3
When it started to occur:2nd day after flashing
Reproducible with the last /e/ version:no previous version (?)
Reproducible with LineageOS:don't know

Summary

When I enter my password to access/unlock the phone or navigate with the File App I can see that it's slightly slower compared to my Fairphone 2 with eelo too. In other words, when I open a window/screen it's slightly slower compared to FP2. About 50% of the memory is used by Android Platform/System

The device is unusable -> Slightly slower but still usable
The bug is the source of a data loss or a big waste of time
The bug concerns a third party app
The bug concerns security
The bug concerns privacy

The problem

Steps to reproduce I don't know ! The problem seems to have appeared after SD card addition (external storage). Concerning the Apps I use :

Orbot is running permanently and TOR to browse
No social network App
APKpure (to install some games I didn't had time to run)
Bandcamp / Qobuz / F-droid / Antenna Podcast / Doctolib / New pipe / Turtl / VLC Didn't had time to run most of these apps. When flashing /e/ I didn't add or modify anything and the fact is that I didn't noticed if the OS was slow just after flashing so I don't know if it was like that since the beginning. I'm using Wi-Fi only, no cellular data. I haven't connected my smartphone to my eelo account as my Fairphone 2 is still connected to it. Not sure it will help just in case.

What is the current behavior?

The screen opening is slightly slower but I can use it and while Fairphone 3 is more powerfull than FP2.

What is the expected correct behavior?

To run at a normal "speed"