Proxy - ERROR: failure while accepting a TLS connection

[zunami]

Hi,

I am getting the following error message on my transparent proxy:

kid1| ERROR: failure while accepting a TLS connection on conn34218 local=IPOUTSIDE:443 remote=192.168.1.10:49478 FD 37 flags=33: SQUID_TLS_ERR_ACCEPT+TLS_LIB_ERR=14209175+TLS_IO_ERR=1

I am unable to connect to HTTPS websites. I get the following error message:
This website is probably a secure website, but a secure connection could not be established. This is caused by internal-ca, ...

I have installed the certificate that I created, but I am still getting this error. 
I cannot find any information about this error code on the internet. 

My settings:

• Opnsense freshly installed
• Adguard installed via extension on port 3000
• UnboundDNS on port 5353
• DHCP server with Adguard IP as DNS

Proxy settings:

• Proxy enabled
• Internal CA issuer created
• Internal server CA created
• CA issuer installed on a Windows computer and marked as trusted
• Enable Transparent HTTP Proxy Port 3128
• CA for Transparentproxy SSL from CA issuer
• Enable SSL Mode
• Enable Transparent HTTPS Proxy Port 3129
• No Bump Hosts: .google.com .googleapis.com .gstatic.com .1e100.net
• ClamAV & ICAP extension installed and enabled

This is my complete configuration, and I am getting the error code "kid1| ERROR: failure while accepting a TLS connection".

Questions: 

• Can anyone help me identify what I am doing wrong? (Based on my information and error code)
• Do I need HTTPS? Or is it that I can only scan external HTTPS connections with the virus scanner in this way?
• Could it have something to do with Adguard?

I would be very grateful for any help on how to approach this issue.