Lightroom Export works well

I have the same HP printer and have had similar problems with lines through image that run parallel to the long side of photo paper. For photos I always select "best" quality setting, so that was not the issue, and I also designate the appropriate paper type. With HP tech support advising me it was determined that the printhead was the source of the problem and needed to be replaced. HP promptly sent a replacement at no charge even though the printer was over a year old. Installation was fairly straightforward with the instructions provided. That took care of the problem but a year later I needed another printhead replacement and this time there would be a charge that just didn't make sense for this printer. I decided I didn't want to invest further. I now have an Epson XP 630 that I reserve for printing photos. It does a very nice job with photos up to letter size, though I find the paper trays quite awkward compared to the HP. I kept the HP 7520 for routine printing of text files, fax, etc. which does not require the quality level I want for photos. It works fine for that and there are no obvious lines through the output pages.