I've been seeing that same thing for a couple of weeks using a Mac with Firefox and Chrome and thought it was my laptop. I was getting pretty frustrated with issues I was having when I'd be on garden.org or facebook and my husband told me that I was working with an outdated operating system so he recently fixed everything for me and updated Firefox to 56.0.2 and Chrome to 62.0.3202.89 ... whatever all that means.
I'm so glad he has technical ability!