Why is my ISP network banned from accessing Dropbox?

Jay, if the traffic was blocked, would such a message even be visible? It's Dropbox generated! More precisely Dropbox forum. If the traffic was blocked, I would never see it!!!

And yes, the above appear only when I use link through https://www.vivacom.bg/. Does Dropbox has some some argues with? Dropbox cuts the link!!!

PS: Till yesterday everything was fine. I just discover the issue. Something happened on your side in meantime.

ADD: More information about the "blocked" network traffic (I hope will be useful for your engineers to trace what's going on):

GET / HTTP/2
Host: www.dropboxforum.com
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:128.0) Gecko/20100101 Firefox/128.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/png,image/svg+xml,*/*;q=0.8
Accept-Language: bg,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
DNT: 1
Sec-GPC: 1
Connection: keep-alive
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
Sec-Fetch-User: ?1
Priority: u=0, i
Pragma: no-cache
Cache-Control: no-cache

HTTP/2 302
content-length: 0
location: https://www.dropboxforum.com:443/t5/errors/FilterErrorHandlerPage
date: Thu, 18 Jul 2024 12:34:42 GMT
set-cookie: ...
set-cookie: ...
server: Apache
pragma: no-cache
expires: Thu, 01 Jan 1970 00:00:00 GMT
cache-control: no-cache, no-store, must-revalidate, private
set-cookie: LiSESSIONID=89D76000DB79839D4E17945746AAFB73; Path=/; Secure; HttpOnly;SameSite=None
set-cookie: ...
set-cookie: ...
set-cookie: ...
x-cache: Miss from cloudfront
via: 1.1 19cd9c9f4eb51e9e5c75add1d4b6f304.cloudfront.net (CloudFront)
x-amz-cf-pop: VIE50-C2
x-amz-cf-id: Y2KQ9s_fxuLSY1z9nbd0gM92_zn33OhpcBVsW2cWs_scoPxON7G-Kw==
X-Firefox-Spdy: h2

GET /t5/errors/FilterErrorHandlerPage HTTP/2
Host: www.dropboxforum.com
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:128.0) Gecko/20100101 Firefox/128.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/png,image/svg+xml,*/*;q=0.8
Accept-Language: bg,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate, br, zstd
DNT: 1
Sec-GPC: 1
Connection: keep-alive
Cookie: ...
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
Sec-Fetch-User: ?1
Priority: u=0, i
Pragma: no-cache
Cache-Control: no-cache
TE: trailers

HTTP/2 403
content-type: text/html;charset=UTF-8
date: Thu, 18 Jul 2024 12:34:42 GMT
set-cookie: ...
set-cookie: ...
server: Apache
x-frame-options: SAMEORIGIN
pragma: no-cache
expires: Thu, 01 Jan 1970 00:00:00 GMT
cache-control: no-cache, no-store, must-revalidate, private
x-robots-tag: noindex, nofollow
set-cookie: ...
x-cache: Error from cloudfront
via: 1.1 19cd9c9f4eb51e9e5c75add1d4b6f304.cloudfront.net (CloudFront)
x-amz-cf-pop: VIE50-C2
x-amz-cf-id: P_EBJ_TijmRuYepv3i7mlvpDOdG_QZq2n0xF5rKB3QewnLS3FCJO-A==
X-Firefox-Spdy: h2

And as result of above "blocked" traffic finally appears the page in OP. Only the cookies has cut.

That's it.

Sheena, As far as know, you are part of forum support tech team. Can you share some thoughts about where that redirect to error page comes from (visible above in the traffic dump, in the first request response)? 🙏😳