topic Re: Intermittent ERR_SSL_VERSION_OR_CIPHER_MISMATCH error in Broadband

Intermittent ERR_SSL_VERSION_OR_CIPHER_MISMATCH error

Harlando2 — Tue, 18 Nov 2025 15:12:29 GMT

When connected to WiFi on my android device, I am getting intermittent error ERR_SSL_VERSION_OR_CIPHER_MISMATCH on chrome and firefox. When I switch to mobile data via Tesco, I no longer get the error. Is there a failed certificate rollout at the Plusnet side? I haven't checked to see if my laptop generates the same issues.

Re: Intermittent ERR_SSL_VERSION_OR_CIPHER_MISMATCH error

MaxSync — Tue, 18 Nov 2025 17:10:35 GMT

@Harlando2

Have a read of this similar forum topic -

Website access problems solved - ERR_SSL_VERSION_OR_CIPHER_MISMATCH

and see whether the solution in the final post works for you ?

Re: Intermittent ERR_SSL_VERSION_OR_CIPHER_MISMATCH error

Harlando2 — Tue, 18 Nov 2025 20:19:56 GMT

Thanks. I will try that. I briefly read it and it suggested workarounds with a permanent fix seeming to lie with Plusnet. I'll also try and inspect the failing certificate chain on my laptop browser to see if that gives any clues. I can't seem to look at the failing certs on mobile browsers.

Re: Intermittent ERR_SSL_VERSION_OR_CIPHER_MISMATCH error

Townman — Thu, 20 Nov 2025 18:30:26 GMT

@Harlando2 wrote:
When connected to WiFi on my android device, I am getting intermittent error When I switch to mobile data via Tesco, I no longer get the error.

Not sure that resolving the issue does lay with Plusnet to fix.

First of all, is that thread relevant to your issue - are you using Parent Safeguarding on your account?
What is the website you are trying to access?
If you are using safeguarding and you want to permit access to that site ... have you whitelisted it?

The fact that the site might be blocked by Plusnet safeguarding (but not Tesco's safeguarding if used) when possibly it should not, is an issue for the site to take up with BT's cyber security team (Plusnet share the same parental safeguarding platform).

Re: Intermittent ERR_SSL_VERSION_OR_CIPHER_MISMATCH error

mrfox86 — Mon, 22 Dec 2025 10:08:16 GMT

I've turned safeguard off, added the affected sites to my always connect, but every time I turn my laptop on at home, I still get:

The connection for this site is not secure

.com uses an unsupported protocol.

ERR_SSL_VERSION_OR_CIPHER_MISMATCH