Your savings is good, but your income won't support that many properties if you do them wrong and need to carry 15k min reserves for each one.Focus on what the next property should be, maybe upgrade to a two-family and see how that goes.

I only received a letter from the appraisal office saying that the value went up but no notice about my taxes going up by 50%.

Most tax preparers include in their engagement letter that you have ultimate responsibility to what is reported on the return.

During that time, I received a letter from the City of Lorain about some violations, including overgrown grass, missing handrails, window frames, and not pulling the necessary permits.

It says in the welcome letter they are required to read it and by staying at our cabins have agreed to the rental agreement.  

I always make my offer and include a POF(proof of funds) letter showing the seller that I have the funds to close.

Answer: No, buying an STR doesn't change the nature of historical passive losses on other LTRs you own and carried forward from prior tax years 

I don't know what your carrying costs are but holding out might make more sense.

They should write you a letter explaining the error and that they are going to charge you the additional $400 now.

@Elias RamirezMail a letter to the property as well - must be getting forwardedBut as mentioned tax bills are being sent somewhere.