Every browser gives me a different result, I guess I can't blame the site for that. But it should perhaps mention which browser would be the most accurate.
I've been a split ergo keyboard user for many years now. Seen a lot of people decide to go from a traditional keyboard to a split ergo keyboard only to end up hating it.
This is too big of a jump to make in one go, and the sudden overhead in the amount of new information your mind and fingers need to get adjusted to ends up overwhelming a lot of people.
When you switch to a custom keyboard like the one you did. It's not just a split keyboard you're switching to, you also move to a smaller form factor that has lesser keys, and an ortholinear layout which has column stagger instead of row stagger. It's most effective to transition by gradually moving to the next form factor only after you're fully comfortable with the previous ones.
In your case, something like the Kinesis freestyle would have been a much better choice for you.