I'm about as low-tech as is possible while being here. My first through is that you may not be doing it correctly, since that was my issue. I don't know about tablets, but it should definitely function on a computer.
For each post except the last one that you want to quote, you click on the button that looks like a close-quotes with a plus symbol below them. For the last of the posts you will quote, you click on the button that's the quill on paper and the word Quote.
If you only use the multi-quote button, it doesn't work.
Tell you what. I'll post a couple more posts here so you can experiment.
Maryn, not doing anything more important