Hi

Is the icon appearing on a second home screen panel?

No its not

What happens when you try to add to homescreen? Is there any error message?

Just got new Moto G Power running Android 10 with Firefox daylight version 95.2.0. "Add to Home Screen" appears in the three dot menu for some websites but not for others. When it does, it's simply doesn't work, no link is added to the home screen and there is no error message. Note this: On my previous phone, a Moto G5 Euro model, also running Firefox daylight same revision level, but Android 8.1, this feature works just fine. So maybe this is an Android issue not a Firefox issue or some combination.

What happens when you try to add to homescreen? Is there any error message?

i have same problem and literally nothing happens when you try. It works on fennec and mull firefox forks.I tried it on redmi 8a miui 12 and redmi note 8 miui 11

Add to homescreen isn't working in Mi devices.

I dont understand why it is working on fennec and mull.(firefox forks)

Sorry, Add to Homescreen magically started working, I guess a week or so ago. I should have updated this. No idea if this is a result of some settings tweak I may have done, or system updates, but the phone is now running Android 11, build number RZBS31.Q-143-27-4, Firefox 96.2.0 (Build #2015858259). Up from Android 10 and Firefox 95.

Aside from what I would call the annoying Feature and Notification -itis creeping into every op system and app, I'm pretty happy now. I just have to turn a lot of default features off to stay sane, i.e. Google ****ing Assistant.

It started working magically a week or so ago. Maybe updates? The phone is now running Android 11 build RZBS31.Q2-143-27-4, up from 10, and Firefox 96.2.0