WSGIServer freezes for large json payloads

[Parkway]

Hi!  Been using gevent (currently 1.0.1) for a few years for the http server ie.

import gevent.monkey
gevent.monkey.patch_all()
from gevent.pywsgi import WSGIServer

application = Main()
http_server = WSGIServer(('server_name', 'port_number'), application)
            
http_server.serve_forever() 

Noticed this past week that the system freezes for json payloads of >100kb.  Today, replaced gevent.pywsgi with the werkzeug run_simple development server and it works.  

Any ideas what might be going on with gevent.pywsgi?