Fonts not the same in saved PDF

Dave, thanks for reply.  I have a newsletter created in Word.  I then save as a PDF, which is always identical to the original Word.  I then place it on my website.  But the new Word makes the PDF bigger, the old made it smaller.  It is now too big for my website provider, 500MB limit.  So I saw I could load it to Acrobat.com, which I did.  It gave me a link https://files.acrobat.com/preview/14b6dd8c-40c6-4011-9101-561b79315846.  But when I view it it is quite a mess compared to both original Word and PDF.  The Arial font is wrong, but it is not consistent, changing from word to word.  Seems odd to me.  Pictures seem to be OK.