UI bug: UI not rendering in Firefox

[Shady-Hegazy]

UI on localhost:9000/ does not render in Firefox.
Instead, it shows plain-text response (header?).

The response text on my device were:
"
ÿ���������T�10.0; Win64; x64; rv:99.0) Gecko/20100101 Firefox/99.0
Accept: text/html,applicatio�/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,/;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encod�ng: gzip, deflate, br
DNT: 1
Connection: keep-alive
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest:�document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
"

This issue occurred only in Firefox.