Page’s Titles and Description are changed

Hi Experts,

I just encountered a very serious issue with most of our pages and landing pages. Today, when I checked on some keywords, we were in the 1st position, but suddenly we dropped down. The reason is that all the Meta Titles and Meta descriptions have been changed. I don’t know how because when I check them from the dashboard, all Titles and descriptions are perfect. However, in Google, we are displaying some other useless data.

Is this due to any plugin, or has our site crashed or been hacked by someone? Please help me.

Please let me know how can I solve it. Here is the site: https://www.uniondevelopers.com

Thanks in advance.

The page I need help with: [log in to see the link]