Following-up from the comments, I understand you have tried multiple steps to isolate the issue:
What specific tier/instance ( Free or Standard etc) are you leveraging?
Based on my understanding of your issue description, for the (too many requests), kindly upgrade the tier and test. example: For Free instances, Concurrent connection count limit is 20. (whereas, for Standard instance is 1 K).
Each client is uniquely mapped to a single application server, ensuring that messages from a particular client are consistently directed to the same server. This mapping remains in place until either the client or the application server disconnects.
Also, checkout this similar discussion thread for more info.
If you have more questions, please let us know.
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