Keyboard freezing up

[Linux for blind general discussion]

I have Debian Buster CLI with BRRLTTY. Every once in a while when I start fetchmail or maybe mutt the keyboard freezes up. It won't respond to anything and BRLTTY 
won't respond to any keys on the Braille 
display. Has anyone had these issues, and have you found a solution?

Thanks,
John

-- 
John J. Boyer
Email: john.boyer at abilitiessoft.org
website: http://www.abilitiessoft.org
Status: Company dissolved but website and email addresses  live.
Location: Madison, Wisconsin, USA
Mission: developing assistive technology software and providing STEM services 
        that are available at no cost