What do you mean by temp phone numbers? Do you mean virtual numbers or real numbers that you only have access to for a short time?
I can confirm that this happens because it happened to me 2 weeks ago.
MY EXPERIENCE WITH SMSPOOL
I tried to create a Google account anonymously by using SMSPool. I used a VPN and did it in Mullvad browser.
First 4 attempts failed
My first three attempts failed. I got an error message from Google that the numbers I used had been used too many times in the past or were not allowed. This was surprising to me, because SMSPool claims they don’t reuse numbers, and that it takes months for them to get reassigned. And when they do get reassigned, they don’t belong to SMSPool anymore.
I wanted to maximize my privacy, so I always made sure that the location of the number I used and the location of my VPN were not the same country. SMSPool advised me to use the same location for both, so I did.
At first, I tried to create a Google account with the same username I had tried to register in the failed attempts, but it failed again. Google wouldn’t even try to send the code. That means that even if a username is not registered yet, Google remembers usernames that someone tried to register too many times.
5th time’s a charm!
Hence, I had to create a new username, which was frustrating, but this time it worked.
I received the code via SMSPool and my Google account was created.
Immediately after creating my account, I went into the security settings and enabled 2FA via authentication app. I also saved all my recovery codes and added a 2nd email address for verification from Addy. I did not add a phone number for 2FA because I knew I was going to lose the number I used to signed up.
I logged in on a new browser to see if everything worked, and it did!
Account locked within days!
I didn’t log in until a few days later, which when I found out my account was locked. When I tried to log into my new account, Google wouldn’t let me access it, even though my password was correct, as was the 2FA token from my authentication app. Despite the fact that my account’s 2FA settings didn’t have any phone number, Google wanted to verify that I am the owner of the account by sending a code to the number I used to sign up.
I couldn’t receive the code, so I clicked “try another way”, except when I did, Google didn’t offer any other way even though I have a recovery email address and recovery codes. It’s messed up. The only option was to recover my account, but when I clicked on “recover” I was right back in the login page.
LESSONS LEARNED
This literally happend 2 weeks ago. I really believed that if I enabled 2FA via authentication app, saved my recovery codes, and added recovery email address I would be fine, but I wasn’t.
1) Use a number you have access to for at least a month
Just in case they ask to veryify you number again.
2) Keep logging into your account multiple time during that month.
3) Enable 2FA via authentication app and all the other 2FA stuff I did.
If you have a YubiKey and passkey to add on top, that would probably help.
I haven’t tried creating a new account again. I’m too frustrated. But I will enventually. I’m just annoyed that I probably have to pay $5 yto $10 to continue to have access to the number I intend to use, for a least a month. There are quite a few online accounts I want to create, and it adds up.
I haven’t used JMPChat, but both SMSPool and JMPChat accept Monero, and SMSPool is now available on the Proxy Store, so you can pay for it with cash if it’s easier for you. Even if you are probably safe using an traceable payment method (credit card, PayPal, bank transfer), I advise you pay anonymously, which means paying cash or using Monero.