Bugzilla

Thanks for taking the time to file this!

Given your gnome-shell version and given that the `GTK_IM_MODULE` thing fixes it, I suspect this is the same underlying bug after all, so I'll dupe it to the main bug report about this, bug 1451466.

Sorry for prompting having prompted you to spin off a new bug -- I was guessing it was different, because both of these aspects are new to me with respect to this general bug:
(1) "can write characters in the password field but it's blinking like clubbing" -- in other bug reports & in my experience, the dialog would entirely disappear after you focus the field.
(2) the requirement for 2 languages/input-methods.
...but now I suspect the bug simply manifests differently on CentOS as opposed to Ubuntu, due to different default languages/configuration.  (Note that most of our reports, including my own experience, come from Ubuntu, so I don't know exactly how this manifests elsewhere.)

Unfortunately there's not much we can easily do to fix this in Firefox, based on earlier investigation (see bug 1451466 comment 29) - this is literally an external piece of software (not Firefox) being hyperactive and stealing focus away from us & then immediately returning it.

To address the issue yourself, you have a few options:
 (1) To fix it locally: you can probably put `export GTK_IM_MODULE=gtk-im-context-simple` in some config file (`.bashrc` or `.profile` or similar), or launch firefox with a script/launcher that sets that env variable before launching it.
 (2) To address it generally for CentOS 7 users: if your CentOS (i.e. Red Hat) version is actively maintained, it's possible you can convince Red Hat (or whoever) to cherrypick the patch from upstream gnome-shell, just like Ubuntu did for Ubuntu 18.04.
 (3) ...or it sounds like an upgrade to CentOS 8 would work.

Thanks for taking the time to file this!

Given your gnome-shell version and given that the `GTK_IM_MODULE` thing fixes it, I suspect this is the same underlying bug after all, so I'll dupe it to the main bug report about this, bug 1451466.

Sorry for having prompted you to spin off a new bug -- I was guessing it was different, because both of these aspects are new to me with respect to this general bug:
(1) "can write characters in the password field but it's blinking like clubbing" -- in other bug reports & in my experience, the dialog would entirely disappear after you focus the field.
(2) the requirement for 2 languages/input-methods.
...but now I suspect the bug simply manifests differently on CentOS as opposed to Ubuntu, due to different default languages/configuration.  (Note that most of our reports, including my own experience, come from Ubuntu, so I don't know exactly how this manifests elsewhere.)

Unfortunately there's not much we can easily do to fix this in Firefox, based on earlier investigation (see bug 1451466 comment 29) - this is literally an external piece of software (not Firefox) being hyperactive and stealing focus away from us & then immediately returning it.

To address the issue yourself, you have a few options:
 (1) To fix it locally: you can probably put `export GTK_IM_MODULE=gtk-im-context-simple` in some config file (`.bashrc` or `.profile` or similar), or launch firefox with a script/launcher that sets that env variable before launching it.
 (2) To address it generally for CentOS 7 users: if your CentOS (i.e. Red Hat) version is actively maintained, it's possible you can convince Red Hat (or whoever) to cherrypick the patch from upstream gnome-shell, just like Ubuntu did for Ubuntu 18.04.
 (3) ...or it sounds like an upgrade to CentOS 8 would work.