Incorrect. I have 6 to my physical address. 3 under my SSN and 3 under my wife.

other family members.

Very weird ...

I have an Amex 4 Target cards loaded but its no longer an option for sending payments.
Thinking that they limited the choices to just 4 I removed some other cards so that I have 3 Visa/MCs and 1 Amex in my profile. When I went back to send money I only had 3 payment choices to choose from... Amex was not one of them.

Very weird...

Edit to add:
I also noticed the cards that my wife and I share (1 card number loaded in both accounts) aren't an option in both anymore.
The card is still visible in the "Add, edit, or delete my credit cards" section in both of our accounts but its only a payment option in one of our accounts... instead of both as before.

I would guess that the cards you see as options to send money have an exact match between name attached to the card and the name on your AP account. They recently changed something that requires name to match. That lines up with why the cards you share are issues - make sure in each account the name associated with the card matches the AP name. The actual name on the card doesn't matter.

I have one card linked with 5 AP accounts using the name on the card. Never had any issues here with cards disappearing.

Name on AP accounts are all different?

That would be strange - I have seen this issue in all 3 of my AP accounts.

i think others have previously reported no issues doing AP transactions outside the US? any recent reports? may try to finish spends on some cards with upcoming deadlines thru AP if we don't manage to spend enough while on vacay ;) thanks!

Correct. As long as the billing address on your card is the same. No problems.
Mistakenly used my friends address as the billing address and it was "Processing" for forever. Realized my mistake. Corrected and it went through.

I have 6 AP accounts.
2 are under my SSN
2 under a SO SSN.
and two that are separate.

I'm churning 6K a month.
All are A > B > Bank.

A > B > Bank
B > C > Bank
C > A > Bank

Easiest way to maximize 1K Send and Receive. ^
Now am I risking it? Sure. I just have some spends to meet. Once I'm done, I'll be cutting back.

I have been doing AP in Indonesia for the past 2 years.

Where you could run into issues would be if you're based here in the US, use a US IP for one account, then complete the transfer using an outside US based IP. That could also throw up a red flag. Best practice may be like some others are doing with home/work PCs or using smartphone (airplane mode on/off method) to perform the transfers. I've been doing that for some time without any issues, but then again who knows what triggers a shutdown.

I assume you are not sending from your 1st AP account to your 2nd? If so, are they going to different banks?

IS anyone using Visa/AmexGCs(200$ bought from office stores) regularly to send money. Does amazon care ?

I've been using $200 Visa GCs for several months with no issues.

Thanks! Do you do all 1000$ with GCs? or you mix it up

It depends, but on several occasions I've done all $200 GCs.