Large payload post requests aren't responding

Have you tried a standard VIP with built in http client profile attached, but *without* the APM policy applied?

If this doesn't work, then it could be one of the default http profile enforcement settings that is dropping the packet.

Check the 'Enforcement' section in the following article (there are quite a few enforcement settings e.g. maximum header size, maximum header count etc):

https://my.f5.com/manage/s/article/K40243113

Also, check the LTM logs to see if you notice any error messages.

Thank I tried increasing the headers and header size but no luck.  I don't see anything in the logs and I'm waiting for the dev to be able to test removing the APM policy

It is mostly this problem: https://my.f5.com/manage/s/article/K25843885