paper server 1.21.10-117
banco 1.2.2
towny 0.102.0.0
Vault 1.7.3
Using gold as money, 1 nugget = 1g, 1 ingot = 9g, 1 block = 81g.
If your balance is bumped into a negative value, the negative value is not corrected when balance becomes positive. Towny death forced a -1g to balance. When a gold block enters the inventory, balance is reflected as 80g. Gold block remains a gold block in inventory, not split into 8 ingots and 8 nugguts. If gold block is dropped, negative value remains in balance.
I have corrected this on my end by disabling negative values, but this seems to be outside of expected behavior.