Copy and Paste Will Not Using the Destination Formatting

I am writing a book in Wood and will submit it to Amazon KDP, and I have set up the document per KDP guidelines. I am working on an English version and a Spanish version at the same time as two separate documents.  The text is justified.  Both documents have Normal/Modify settings set up exactly the same.  The Fonts and Paragraph settings are exactly the same. I have gone into the Options/Advanced area of Word and played with all of the Cut, Copy, and Paste settings to try to fix my problem.  But I can't figure out what is going on.

I created the Spanish document by using Google Translate to take English paragraphs, translate them, and pasted them into the Spanish document

The Spanish document is completed, and all of the formatting looks fine. So I already have paragraphs that are a certain size in the document, meaning they take up a certain number of lines.

I am now editing the book using the English document. Something has changed with the Spanish document!

If I make a small edit in an English paragraph, use Google Translate to deal with the edit and do a new translation, and then copy and paste that edited Spanish paragraph from Google Translate back into the same place as the original paragraph in the Spanish document, the words are slightly more compressed together, so the paragraph gets shorter!  This happens if I even change just a single word in a paragraph, which has not really changed the length of the translation. The paragraph will become shorte by a half of a line, or a full line on long paragraphs.  This is all becasue the words are being spaced slightly closer toegether now, versus when I originally crated the document.

Also, when I start to do the paste, from Paste Option only get the option for "Keep Text Only."  I don't get the multi-paste option box.

Something has changed in my setup of Word from the time I created the original Spanish document, and what is happening now.

I can't figure out why the formatting of the destination, or using merge formatting, is not working!  It's making up it's own jutification spacing all of a sudden.  I can't figure out why now a cut and pasted paragraph from Google Translate is making the spread between the words just slightly tighter.  The latest thing I tried was Review/Language and choosing Spanish for the Spanish document, and that did not work.

Any ideas?

Gordon