Without showing us your HTML is it going to be hard to say. If you're using a third party framework like Bootstrap it is possible it is overriding your settings. If you have additional CSS classes applied they can stomp over things as well.
The easiest way to figure out what is going on is to load the page in the browser and do the following:
- Open the developer tools (F12)
- Use the
Select an Elementtool in the top left corner to select your button. This takes you to the corresponding HTML. - On the right side is the
Stylestab. It will show you what styles are being applied and from where. The topmost styling wins. You can uncheck and check styles to remove/add them to test things out. If you still can't figure it out then go to theComputedtab and find thetext-alignproperty in the list of CSS properties. It will show you who ultimately is controlling the setting.