V2RayXS does not import a subscription when the subscription body is plain text containing a valid VLESS link.
The same VLESS link works if imported manually.
The same subscription URL is successfully fetched by the app (HTTP 200 in console log) but new servers doens't appear in list.
If I convert the exact same subscription content to base64, V2RayXS imports it immediately.

This makes it look like plain-text subscription content is not handled correctly in the Update Subscription flow, while base64 content works.

V2RayXS: 1.5.10
macOS: 14.8.3
url: https://domain.com/sub.txt?md5=...
content: plain-text file containing exactly one line
vless://123@1.1.1.1:443?type=tcp&security=reality&pbk=123&fp=chrome&sni=domain.com&sid=123&spx=%2F&flow=xtls-rprx-vision#test

1. Open Configure -> Advanced -> Subscription
2. Add a subscription URL
3. Click Server -> Update Subscription
4. Observe that nothing is imported
5. If I put in the same file on the same url the same content but after

base64 < sub.txt | tr -d '\n' > sub.txt

V2RayXS imports it successfully.

Question:
Is plain-text subscription content expected to be supported for VLESS links in 1.5.10?
If yes, this looks like a bug.
If no, it would be helpful to document that subscriptions must be base64-encoded.