You aren't talking to Apple here, just other users like yourself. The channel to report bugs is
In system preferences/users & groups/login options, have you checked the box for Show Input Menu at Login Page?
Thank you Tom.
As suggested, I submitted this as a feedback as well.
I also checked the box for Show Input Menu at Login Page in system preferences/users & groups/login options. I will see whether it suffices to resolve the issue. My first attempt after checking this option was not very successful. After putting the mac to sleep and trying to wake it up, I got the spinning wheel and had to force shut down.
Anyway, I will update this thread as soon as I have been able to test the suggested strategy.
Here is the promised update (sorry for the delay).
In the strict sense, the issue is resolved as per Tom Gewecke's suggestion. It cannot be considered a "bug," since there is a way to circumvent the problem. Yet, I would suggest that this remains an issue insofar as the default setting still makes the login screen behave in a way that is unacceptable. The fact that users have to tweak the preferences in order to obtain an obvious result can be considered bad design of the OS at this level.
I would recommend that the Apple programmers simply improve the interface in this regard and be a little more "international" in the way they test the system.
In any case, I really appreciate the help received through this channel.