Delay on keyboard layout switching

First of all thanks for the great work of all volunteers to make such a great and modern desktop environment.

I noticed that switching the keyboard layout, either via the keyboard shortcut or by clicking the top panel causes some delay. Sometimes even 5 seconds in a very modern computer. During this time the whole GUI freezes... even other windows.

Seems that this is happening since GNOME 3.28. I tried in Ubuntu 18.04, 18.10, Fedora 27, Fedora 28 and Fedora 29, Manjaro and seems to have the same issue.

This bug report seems to be the same problem. That's where I got the workaround. I decided to report upstream because it seems to affect multiple distros and it is quite basic feature for those who work with multiple languages. https://bugs.launchpad.net/ubuntu/+source/console-setup/+bug/1370953 https://bugs.launchpad.net/ubuntu/+bug/1388770

The workaround that I found that has instant performance on switching layouts is to set to set a script to run automatically the following command:

setxkbmap -layout us,th,pt

The layouts on the command need to be put in the same order as the gnome menu shows otherwise could lead to inconsistent behaviour (the layout shown is different than the current layout).

Sorry, but I'm not in conditions to judge what is the cause of this bug, but one humble suggestion, with my limited knowledge of the matter... maybe if in future versions, if the bug cause is difficult to be found, one possible workaround that could be implemented would be to run automatically the command above behind the scenes on the backend with corresponding selected layouts by the users so to offer a more smooth keyboard layout switching.

Thanks and congrats for the great work!