Strange problem after september updates (IPSEC / revoked cert / let's enc chain)

[Bestig]

Hello, after a recent changes, i faced a strange issue:
from my new (just unpacked) dell Laptop, i can open with chrome URL https://revoked-isrgrootx1.letsencrypt.org/ without any problem (which i shouldnt really). It says cert is ok and everything is fine.

The strange thing that i installed a new root .cer and everything else tried, but nothing really changes - i sitll can open revoked site via chrome/edge without any problems.
The main problem is that i can't connect to my IPSEC (strongswan) VPN from this notebooks, it says problem with .cert. But i can open a https://valid-isrgrootx1.letsencrypt.org/ and it shows decent new cert (expiring 2035, and R3 expiring 2025 in chain).

tried:
restarting
certutil -urlcache * delete
connect to VPN from diff PC (mac) - works fine, not vpn/username/pass issue

any suggestion pls?

[rg305]

Hi @Bestig welcome to the LE community forum

@Bestig

any suggestion pls?

Try:
Support for urgent Trusted Root updates for Windows Root Certificate Program in Windows (microsoft.com)

[Bestig]

Hello, i'm afraid it won't help - article is for Windows 8.1 or lower, wer using windows 10 and today fully updated windows - it didn't help.

[rmbolger]

Just to verify, your VPN is using a Let's Encrypt certificate, right? If so, we're probably going to need the hostname to help any further. The most common issue would be that it's not serving the chain properly (or at all).