Title block doesn't work

I want to add poll to my website, I installed WP-Polls plugin and created one which I later added to my website. Everything works fine but I want to add title above poll. So I added empty row, then I divided it like 1/3 – 2/3, on left side which has 1/3 of row space I added block title, and also had idea to add one inner row beneath block title and to place poll in inner row. But problem is that I can’t add title block, later I found that I actually can’t add title block nowhere on my page. When I try it it’s loading but nothing happens. If I click save while it’s still loading or if I try to add it by adding shortcode, when I reload page the following message appears at very top of the page: Warning: Illegal string offset ‘custom_title’ in /home/mvmedia/host/subdomains/dev.mega-media.hr/wp-content/themes/Newspaper/includes/shortcodes/td_block_title.php on line 22. I only want to have poll with title, if you know any other way of doing it please let me know.

I found that problem was in shortcode, when I was adding “title” element in shortcode it appeared like [td_block_title] but it was supposed to look like [td_block_title custom_title=”TITLE GOES HERE]. But now I have other problem, every time when I do any change to my website, let’s say for example when I add new element and save it, poll just dissapear from page?