While performing RCA for one of our client's website, we found that there are multiple hits where value of Adobe Experience Cloud Id (mcvisid) is populating as 0. Considering this as bot traffic according to answer posted on (https://forums.adobe.com/thread/2438740) also doesn't give meaningful result here as the percentage of hit having mcvisid is very high.
Upon further analysis we found same IP has one instance as mcvisid=0, and other instance with some value with the same domain name.
There are also hits recorded where visits>=1 and pageview=0 for mcvisid=0 and considering this as s.tl() call is a very rare instance.
We will be very grateful if anyone from community can help us finding the reason.