Hi, I'm using the same version of Mendix Studio Pro and it works well for me. The only important diff may be that I'm using different profile: Phone web offline. Probably the OFFLINE aspect is crucial (although the docs are somehow mysterious about how it works for ONLINE profiles).
https://testmx9pwa-sandbox.mxapps.io/
https://testmx9pwa-sandbox.mxapps.io/manifest.webmanifest?637510757022786320
Tried to set a few props in my theme/manifest-overrides.webmanifest and it did affect the PWA installation, e.g. names and colors have replaced the default values ("Mendix" and white):
{
"short_name": "TestMx9PWA",
"name": "TestMx9PWA: PWA on Mendix 9",
"background_color": "#99FF99",
"theme_color": "#FF8000"
}
The generated manifest.webmanifest:
{
"name":"TestMx9PWA: PWA on Mendix 9",
"short_name":"TestMx9PWA",
"background_color":"#99FF99",
"theme_color":"#FF8000",
"icons":[{...}, {...}],
"dir":"ltr",
"start_url":"./",
"lang":"en-US",
"display":"standalone"
}