Maximum three online users shown

[evcom]

Since a few days I have the issue that only a maximum of three users are shown in "who is online". Myself (admin) a logged-in user and a guest. This behavior is also shown in the ACP.
After May 30 a sharp drop is shown. Before that an unusual increase in traffic (bots?).

However, Matomo shows all visitor traffic, also after May 30, correctly 

The site was upgraded to 4.7.17 on June 8. However, the problem appeared before, around 30 May.
The SPAM defense log shows since this date only IP addresses with 127.0.0.1 and it seems also users with only this assigned IP are shown in "who is online". 
Is there any setting that can ban/allow IP addresses in Invision Community? 

Any help much appreciated. 
 

[Jim M]

34 minutes ago, evcom said:

Is there any setting that can ban/allow IP addresses in Invision Community? 

These would still be online users in this case, even they are banned. However, there is ACP -> Members -> Ban Filters. There is nothing in our software which would take them outside of this and likely would be an external firewall if so.

[evcom]

Thanks Jim. I am still investigating and could not resolve it yet. Matomo Analytics shows all users that are coming in, no specific drop observed. So users can access the site. However, this is interestingly not reflected on the "Who is online" widget. So Invision does not seem to track visitors anymore. I have some PHP8 incompatible customizations on my site. So I will disable them to see if that resolve the issue.