ok I think I figured out the issue, in one of my games there is a guy named "Administrator" and hes cool, lets me invest and take out a loan (although I never tried the loan feature) And in my next restart I used a mod to give myself some starting money just so I can run straight to the bank and start investing, but Administrator has been replaced by someone named "Banker" and he is just a jerk. Not sure why he in there, in my first interaction with Administrator it was still really early in my game, not sure what could be different (although I did remove a lot of mods before this problematic start, not sure how removing a mod can cause an issue)

Perhaps my poor knowledge of English prevents me from understanding the essence of your comment, but this is how I see the situation. I hope if it is not so, you will correct me. There are two bank employees in mod – an administrator and a cashier. The receptionist is a friendly guy who often stands at the counter in a noble robe. He provides the possibility of a loan and a deposit, as well as provides explanations for all questions. The cashier is a rude, tired bureaucrat who issues interest on deposits, as well as interest on the caravan. Perhaps you turned to him. I do not know for sure, since I was not involved in the transfer, and perhaps the Banker is the cashier. Then there's nothing you can do about his rudeness, that's the character) However, there is also a possibility that you have another mod for the bank, and the Banker character is from there. I also want to remind you that you cannot invest money immediately after the loan, as well as interact with the bank until the loan is paid.

"Cashier" is the person who lets me collect interest on investments, and to invest in caravan.
"Administrator" is the person who lets me invest or take out a loan.
"Banker" is the person who is rude and just insults me.

In my current game there is no "Administrator" there is only "Banker" and "Cashier"

Sorry, I sometimes talk too much

Also "Banker" wears same clothes as "Administrator"

The first time I played with this mod there was only Cashier and Administrator.

I checked my mod list and I dont have any other bank mods, also CIB is at the bottom of my mod list

in general, I checked the mod both in the game and in FCS. There is not a single character named Banker. Only the receptionist, the cashier, and the debt bouncer. The third does not appear in the city where the bank is located. Apparently, it's still some other mod that adds this character you're talking about, since physically, he's not in my mod.