If a website works in one browser but fails in another while the VPN is connected, an extension or browser setting may be involved. Start with that comparison instead of reinstalling the VPN.
Record what differs
Note the affected browser, the website, the exact error and whether another browser works on the same device. Keep the network and VPN state unchanged. A change of browser and network at the same time would not isolate the problem.
Review extensions that can change network routing, block page resources or alter site data. A browser proxy can affect the address seen by websites independently of a system VPN.
Test one optional extension
On a browser you manage, open the extensions manager and temporarily turn off one optional extension you suspect. Reload the same page and repeat the failing action. Restore it before testing the next candidate so you can identify which change mattered.
Do not remove employer-required controls or disable browser certificate checks. If a managed extension is involved, give the administrator the comparison result.
Read the outcome
If the page works only with one extension off, check that extension’s documented site settings, permissions and updates. A narrow per-site adjustment may be enough. If the symptom persists with optional extensions disabled, investigate cookies, DNS or the service itself.
The browser information tool can help you record browser context, but it does not list or diagnose installed extensions. Use one-website troubleshooting for the next branch.