Ok seem the Gold Build Bug is still there, tested it by getting 201G and building a Room for 200G, all money went. idk if this helps but I'm only Day 23 into a new save, already have the Elf and Centaur as guests, 3 rooms, test was made building the 4th room. my only observation is the bug starting after I get the elf as a guest.
I'll start up a new save once I get back from work, and see if The Elf is the cause by not getting her as a guest and see if the issue persists. I'll try all sorts of Angles and see when the issue truly does manifest.