@jimy2004king, yes that is weird decision for jsonschemalint.com and very unfortunate coincidence for us.
jsonschemalint.com use different validators for different versions. AJV for v4 and JSV for v3.
JSV is slow and buggy. It validates your instance against v3 just because it seems that is doesn’t care about format at all: notice for example format: uri in this snippet.
AJV is very flexible and has lots of features, but those features don’t have much in common with specification which I linked before.
As I said this is very unfortunate coincidence, because we didn’t have such problems with online validators before (I think jsonschemalint.com changed its validator core very recently). We at Snowplow use this validator (previously known as fge’s) at enrichment, shredding and all other places. You can use its online version to be sure which JSONs will pass validation and which will not. However, I found important differences with online version and our apps: 1) it doesn’t understand self-describing JSON’s self property 2) it marks unknown formats as errors.
Once again, we didn’t have these problems before and used to rely on online validators, however it seems that we need to reconsider their usage. So, thanks for raising.