Why do I have two property tax account numbers? I just got a second set of bills that’s (apparently) 7 months late and I’m confused

So in the middle of 2019 I moved to a new address (in Cypress) and elected to not have an escrow account. January rolls around and I pay all of my taxes that were mail to me. All of which I paid via entering my account number on cfisdtax.com, utilitytaxservice.com, etc. As my house was new construction, the taxes only reflected the land value and no improvements. This seemed pretty normal as I remember my last house (also new construction) had the same sort of very low 1st year taxes. I was done, or so I thought.

However I have just recently received another set of tax bills from these same places with, what appears to be a 2019 prorated tax on my improvement value. So be it, I can understand that. The tax statement is dated 8/20/2020, but it is apparently already 7 months late as it was technically due by January 31st and they are asking for interest to be paid. Now hold up here, if I JUST receive the bill how can I owe interest on it?

When I log onto the above sites (cfisdtax.com for example) and enter my name it shows two separate accounts. One for the land value and one for the property value. Almost like they are split up and last year I only receive bills for one of the accounts.

I searched for all my neighbors on the sites and all of them only have one account. Very odd…. I'm not against paying the taxes but it seems pretty dirty to be asking for 7 months interest when the bill was just mailed (it even says this on the websites as statement mailed date)

Does anyone have any idea whats going on? I'm going to call all their numbers tomorrow and see what I can't find out, but I figured I'd see if anyone had seen something like this before.

TLDR: Moved into a new house. Paid property taxes. Now getting second set of bills from a second account number (with my name and address on it) that is 7 months late. Why?