Why don't my stock purchases go through?

I'm doing the assassination missions and playing the stock market. I have around 180 million at the moment. The problem I'm having goes roughly like this:

1. I pick a stock on the market and enter the 'buy' page.

2. I press on the '+' button until it's at the max amount of shares.

3. I press 'buy'.

4. On the next page, I click 'confirm'.

5. On the page after that, I click 'continue'.

6. I am shown my portfolio page; my portfolio is empty and no money has been removed from my account.

This has happened for several different stocks, so it's not related to one particular company. I tried breaking up my purchases into smaller chunks and that worked. So I'm thinking maybe there's a maximum $ value for each transaction, or a maximum number of total stock per transaction. Anyone know what's causing this issue? Is it just a bug?

Sometimes when you hold down the + button it goes over the max amount you can afford, usually by 1 share. Once you get to the max remove a few shares and it usually works. Had the problem when I was trying to do the assassination missions.

Happened to me too. Just buy 1 share first and the it’ll be in your portfolio, after that buy as many shares as you want.