Hello,
I am really surprised that noone has found out about this one yet, or didn't submit it.
So, when enabling non automatic rents, where I have to press space to claim the Money, I am able to build after the Landing of a player on my property and then press space. For example I have one house, the player rolls and lands on there, I am able even to mordgage other properties, gain more Money, build few more houses and then press space to get much more Money than I would with one house. Here is history log with a concrete example:
It's Dark vador's turn.
Dark vador rolls the dice: 1 3.
Dark vador advances by 4 squares.
Bienne
It's your turn.
You have 13 400 francs.
Choose the property where you want to build a house:
You build a house on Bienne. There are now 2.
You build a house on Fribourg. There are now 2.
You build a house on La Chaux-de-Fonds. There are now 2.
You build a house on Bienne. There are now 3.
You have 5 400 francs.
You build a house on Fribourg. There are now 3.
You build a house on La Chaux-de-Fonds. There are now 3.
You don't have enough cash.
Choose the property to mortgage:
You mortgage Lausanne and get 3 500 francs.
You mortgage Genève and get 3 000 francs.
You mortgage Montreux and get 2 800 francs.
You have 10 700 francs.
You build a house on Bienne. There are now 4.
You build a house on Fribourg. There are now 4.
You build a house on La Chaux-de-Fonds. There are now 4.
You build a house on Bienne. There are now 5.
A huge construction is on the land, which seems to be so idyllic.
Dark vador pays you 19 000 francs.

Hello,

What a funny bug, gg!
I'm unsure yet how exactly I'm going to prevent this, but thank you very much for signaling.

I think it wasn't signaled before first because non-automatic rent isn't a very popular option, and secondly also probably because relatively few people have got that quite twisted idea in mind.

Yeah it's funny but also a bug that could be misused, perhaps I shouldn't have reported it publicly.
I noticed something else while playing with bots, I thought that it occured because you tried to prevent the mentioned bug from happening. The problematics is as following:
If player A, rolls the dice and lands on my property, and player B immediately continues rolling, if I did not press space before the roll of player B, I won't be getting my Money. Sometimes this happens with bots because they simply decide to take their turn quite fast. I don't know if you could set a time limit during which I still can claim my Money even if the next player rolled the dice.
I got few other Monopoly bugs to report but for now I am collecting them and will make another post.