After my install all of Android 10 to my fairphone3 I sometimes cannot get the phone to record my voice from the g keyboard whenI do voice to text no when I do voice notes.
Also at times it won’t let me hear when somebody is speaking to me on a phone call this happened several times with my wife and once with a colleague from work
Yes, you need a computer. Install instructions are here … Install /e/OS on a Fairphone FP3/3+ - “FP3” (the “Installing a custom recovery” section is a temporary documentation error, doesn’t apply to the Fairphone 3 and is about to be removed).