The error that you illustrate might suggest that the App is attempting to make an unexpected TLS/SSL connection to a network resource or URL that Norton, for some reason, has blacklisted.
Due to the system architecture of iOS/iPadOS, unless jailbroken, your iPad is not susceptible to traditional malware infection per-se. However, as with all computer systems, there are still vulnerabilities and exploits to which you remain vulnerable.
Any App that claims to provide AntiVirus capabilities for iOS/iPadOS is nothing more than “snake oil” - and is best avoided. Apps that provide network filtering are doing so via a network proxy connection; these may have limited efficacy.
Norton, as a brand, is perhaps one of the better examples. It cannot provide AV protection, but can provide a network proxy with which to examine and identify suspicious network/DNS traffic. The error that you see should, perhaps, be taken seriously. If in doubt as to the provenance of the App to which the flagged-connection is associated, you would be well advised to consider its removal from your system.
Setting aside Norton, for iOS/iPadOS, browser-based attacks can largely be mitigated by installing a good, trusted, Content and Ad-blocking product. One of the very best and most respected within the Apple App Store - explicitly designed for iPad, iPhone and Mac - is 1Blocker for Safari.
https://apps.apple.com/gb/app/1blocker-for-safari/id1365531024
For older devices that cannot support iOS/iPadOS13.x, 1Blocker Legacy provides similar capabilities for iOS9 to iOS12:
https://apps.apple.com/gb/app/legacy/id1025729002
1Blocker is highly configurable - and crucially does not rely upon an external proxy-service of potentially dubious provenance. All processing takes place on your device - and contrary to expectations, Safari will run faster and more efficiently.
Unwanted content is not simply filtered after download (a technique used by basic/inferior products), but instead undesirable embedded content blocked form download. A further benefit on metered services, such as cellular connections where you data may be capped or chargeable, this not only improves speed but also saves you money.
When using an effective content blocker product, a high proportion of otherwise inescapable risk when using your Safari browser, or linking to external sources from email, is effectively mitigated before it even reaches you.
A further measure to improve protection is to use a trusted Recursive DNS Service in preference to automatic settings. This can either be set on a per-device basis in Settings, or can be set-up on your home Router. I strongly recommend using one of the following services - for which IPv4 and IPv6 server addresses are listed:
Quad9 (recommended)
9.9.9.9
149.112.112.112
2620:fe::fe
2620:fe::9
OpenDNS
208.67.222.222
208.67.220.220
2620:0:ccc::2
2620:0:ccd::2
Cloudflare+APNIC
1.1.1.1
1.0.0.1
2606:4700:4700::1111
2606:4700:4700::1001
Use of the above DNS services will help to shield you from “known bad” websites and URLs - and when used alongside 1Blocker, provides defense in depth. The protection afforded by these DNS services are very similar to that offered by Norton - in that “bad” websites and network addresses are blocked.
I hope this information proves to be helpful in resolving any difficulties.
