Who I have the same questioned this topic

Twice in the past 24 hours I have had occasion to call 800 numbers (different numbers).  Both times, I had to resort to my landline to make the call, which handled it perfectly, and I'm thankful I still have a landline!

What happens is this:  I dial the number (and I've tried it multiple times, with and without the leading "1"), press the call button, and the screen immediately goes to "Call ended".  It's like it never even tries to dial it.  I am the account owner, the only manager on the account, and we have never restricted calls on this account.  All the lines belong to adults, no need for calling restrictions.

Other calls go through on the phone normally.  I've dialed 800 numbers previously, successfully.  Why would it not work now?

Galaxy S6, HD calling is currently OFF, due to call quality issues when it was on.  Battery was charged with more than 50% remaining in both cases.

Anyone else experience this?  I could only find one other post, nearly a year ago, and the only reply was to ask about the leading "1".  can't call a 800 number from my phone