[orca-list] On Firefox/Thunderbird: when starting Orca, it is extremely sluggish to detect the current position

[Alex ARNAUD <aarnaud hypra fr>]

    Hello all,
    
    Environment:
    - Debian 10
    - Firefox Nightly / Thunderbird Daily
    - Orca 3.36.x and Orca master
    - Mate with Compiz
    
    Steps to reproduce:
    1) Launch Firefox Nightly on this
      page for example
    2) Launch Orca, here with the shortcut control + alt + o doing "orca
    --replace"
    3) Orca starts and says "screen reader on" and nothing more during
    more than 10 seconds
    
    Result:
    Orca takes more than 10 seconds to announce the current position.
    
    Expected result:
    Orca should react quicker as it does before.
    
    Note:
    I don't have made many upgrade on my computer, I'm pretty sure it's
    a change on Firefox/Thunderbird Nighlly/Daily side which impacts
    Orca.
    After Orca has started, the reactivity is correct.
    
    Thanks in advance.