Founders, what's the biggest challenge you've found in managing remote dev teams?

Looking for your thoughts, thinking about how to best manage remote devs in this environment for my company. Thanks :)
I don't run a team of remote devs myself, but have seen articles I like come out of X-Team:
@lynchen, I've been working with remote development teams for four+ years (as a Scrum Master/Agile Coach) and recently wrote an operating manual, in case it's of use to you.
Becca, I read the manual, thanks for putting it together, I really enjoyed reading it, a good reminder that being a decent human being is the foundation for making any team work
Thanks for your feedback, @lauravidalborrell! I really appreciate you taking the time to read it.
Thank you for this resource!!