I have realized this is happening in Windows 10 as well as Linux, so I'm posting here.
I need to use AltGr in Firefox mainly as shortcut with back and forward arrows — for previous and forward page/address, something which is default in Firefox as well as in other internet browsers.
- In those other browsers, these shortcuts work with the keyboard layouts that I use — in Firefox they do work with the main one (English-US) but not with the others that I use: French, English-US international (just in Windows), English-US international with dead keys (just in Linux), and Romanian standard.
- I have tested this with a new, pure, addon-free profile of Firefox, as well as with some Firefox-based browsers (LibreWolf in Linux): the same thing happens.
- The other Alt-key (the "normal") one at the left of the keyboard works in all cases.
As I find myself often using different keyboard-layouts when navigating with Firefox, and because I am using AltGr+Arrows all the time, this becomes very confusing sometime.
How to troubleshoot this? What could the cause be? The fact that the keyboard is changed doesn't work as an explanation for the default shortcut to stop working.
**Should AltrGr count IN ALL CASES as a proper key for the default shortcut involving Alt? This seem to be the case in Chrome or Edge.
Or maybe this is normal, given AltGr "is primarily used to type characters that are not widely used"** But this only happens in Firefox.
The fact that in some layouts AltGr is the main modifier for special characters could be a sufficient explanation for what happens (AltGr would on such layouts be reserved for that purpose and stop acting as a normal Alt). For example, in US International, AltGr is indeed modifier for many special characters (with
qwertyui ETC it gives
äå®þüúíóö«»áßðø¶´¬æ©æ©ñµç¿); in French, in combination with
] it gives
¤; on Romanian standard layout, with
păîsdlșțâc,., it gives
Why this is the case only in Firefox cannot be justified by this line of reasoning. Chrome, Chrome-based browsers, Edge of Microsoft, are very well able to keep providing the default shortcuts that I need with AltGr on all layouts without affecting the provision of special characters by those layouts.
Can this Firefox situation be changed by some setting in
As said in the answer (and discussed in a question like this), there are keyboard layouts that trigger the same problem in Chrome and other browsers, depending on the keyboard layout (and therefore my initial assumption that only Firefox was affected by such layouts is false). Only by change the layouts that I use (mentioned above) are affecting Firefox but not other browsers.