So I was perplexed why your results were so different than mind. The I realized that the only variable I hadn't tested was the rom. Turns out that my old stash of roms are degraded. While they worked for initial testing in other emulators, the longer I played glitches showed up. I tried a new Castlevania rom and tile mode worked perfectly. I'm sorry to have wasted your time on a red herring.
Martin