The problem that you have encountered is known issue from Sequoia 15, see the below screenshots :





Source :  https://discussions.apple.com/thread/255765230?sortBy=rank



To resolve the issue check the below source and screenshots :







Follow the below guide:

Option I: Remove the Network filter


1. On your macOS device, navigate to System Settings.

2. Click Network → Filters.

3. Select ESET Network and click the minus icon to remove it.

4. Restart your macOS device and check if your network connection is functional.

5. From the ESET Website, ESET Endpoint Security for Macos Version 8.1.6. supported  Sequoa 15 , see the below screenshots:
You have 2 options 

Option 1 -  If the ESET Management Agent is still connected and you only uninstall ESET Endpoint Security from Macos , therefore the machine still be connected and you can install EES for MacOS using software install check this source : [KB7654] Deploy or upgrade ESET endpoint products using ESET PROTECT or ESET PROTECT On-Prem

Option 2-  Since you are about to create a new installer Sequoia 15 Macos , machine I highly recommend to you to choose 'ESET Endpoint Security for macOS (v7+) because that is the compatible version for  Sequoia 15 Macos