Are you able to reproduce this with the ThreadX-NetX_Duo build?
Can you let us know if you had luck with Netx/ThreadX
It has different symptom on ThreadX-NetX/NetX_Duo.
The ERR_INVALID_CHUNKED_ENCODING happens on FreeRTOS-LwIP build.
The file transferred truncated happens on ThreadX-NetX build:
We found the web does not properly show on browser.
Use google chrome to check the network transfer and found the file size
does not match.
Note, test.css is 132K.
$ du -sh resources/apps/ping_webserver/test.css
Attcahed 2 screenshot to show the file truncated cases.
The 2 screenshot show different size transferred, both have file truncated issue.