My ERP module connects via API and sends 1k of the product's data when there are changes from my ERP side. In the logs, I just see the message below and my stock hasn't been updated.
Web API is unable to process.
I think it's something new in Magento 2.4 since I just updated from Magento 2.3 and the issue started. How could I solve it?
It's happening because in the new Magento versions 2.4.3 and 2.3.7-p1 we have built-in Web API limits.
REST requests containing inputs representing a list of entities are limited to a default maximum of 20 entities to avoid DDoS attacks.
I recommend spreading the requests in small requests and not have a huge amount of data in one request or a short period of time instead of disabling or increase the built-in API limits.
To disable the input limits on the REST API request, apply one of the following patches (depending on your version):
MC-43048__set_rate_limits__2.3.7-p1.patch.zip
MC-43048__set_rate_limits__2.4.3.patch.zip
Reference here and API security.