I will cite the OpenAI employee who finally found the root cause of this bug and announced it in OpenAI’s discord yesterday morning:
Hello all! The root cause of this was pinpointed and affecting a subset of users. If you experienced this, please send me a DM with your account email address.
I’m sorry for the issue here and greatly appreciate your understanding that we are a growing product.
I DM’ed him on discord and the issue was fixed for me, also I was refunded and got 1 month for free as a result: