Portal isn't allowed to post submissions

[Target]

We have different customers who want to receive their lead data via hubspot, for most of them this is working fine.

For one, we receive this response and it is not clear what is going wrong.

{"status":"error","message":"Portal isn't allowed to post submissions","correlationId":"e6a020a7-02e6-46d6-aaaf-227979aa14d9"}

If there is an issue with the form, the response is pretty clear. I found another post which mentioned to use an api-eu1 endpoint. That works fine if we test it on other forms, but for this client, again same error.

Any ideas? I cannot find any relevant answers online.

[TomM2]

Hey @Target I'd guess either you're hitting a rate limit if you're doing a lot. How many submissions are you sending per second, and what hub tier is this portal on?