I ran into a problem when using large (JSON) body with HTTP requests. They worked fine locally, but when I deployed the server application to Google Cloud Compute instance the requests were not received completely. They were cut around 82 kBs. I noticed that all worked fine when I connected directly to the instance without using the HTTP Load Balancer in the middle. Also tried out the Network Load Balancer configured to use port 80 and it worked. So it seems the problem is caused by the HTTP Load Balancer.
Have anyone found a solution to this? I would like to use the HTTP Load Balancer, because it fits my requirements better (for example you can add instance groups as the backend target, on Network LB you need to specify each instance separately).