Probably totally unrelated, but I've been having weird Internet problems for the past couple of days.  Things like what the OP said above.  I'm having sites come and go from reachability.  Like right now I can get to www.speedtest.net, but not the test itself.  I can get to USPS.com, but not the PO Box management or login page.  Slushpools zcash pool has been more offline than online to me, from here at the Farm, but apparently is fine from my little PC in St. Louis throwing crumbs at it.

Last night my wife could receive messages on Telegram but not send them.  Our house has its own static IP, my office has another with the same carrier and Telegram worked fine for me.  This morning she was fine.

Its weird and more than a bit frustrating.

Just thought I'd mention it in case it IS somehow related (like a mid-west USA network wide routing issue).  Note that DNS lookups are working fine.