I found this question while trying to solve this myself and it may be too late but I figured it out!
Go to Edit Code>snippets/tab.liquid
at the top of the page above {% if output_tab %} replace that code with this:
{%- liquid
assign output_tab = true
if title == blank and content == blank
assign output_tab = false
else
if title == “[name of your tab here]”
assign force_open = true
endif
endif
-%}