html doc. changes margins to .20 below paragraph

For years I have wanted to ask this, though it is easy to revert:
I created a document in writer, using a template that has “below paragraph margins” as 0.00, and which usually contains with tables, and save directly or later as html (after being .odtl), which I have done for multitudes . (LO is the best WYSIWYG html editor.) I find that i must have no spaces btwn paragraphs or else when rendered in browsers there will be a large space btwn paragraphs.

I close the html doc and later reopen it, and find out that the below paragraph margins have gone from 0.00 " to 0.20 ". I thus select all and change the margin to 0.00 ".

I suspect I am supposed to create a template with certain formatting options, though I have later tried changing some in Styles and Formatting for tables.

I am using LO Version: 4.4.2.2