Something Not Quite Right

I’m trying to update and print out a list on A4 paper. I use a Canon MG2500 printer and Windows 10.
When I updated and tried to print out my documents I noticed that part of the first letter on the left of each page was missing and the last 3 lines of each page at the bottom was missing.
How do get the printer to print out to the bottom ? I have moved the text in from the left a little and that seems to have worked (but I shouldn’t have had to - worked OK before). What I mean is, I don’t know if the printer is at fault or if I’m doing something wrong in Libre Office.

No one else has your printer, how should we test it? Make your document anonymously available. Edit your question and then upload the file.

What are your pages and margins?

From your terse description, I infer that you try to print edge to edge. Every printer has mechanical margins where printing in not possible. Therefore you need to make LO margins at least as wide as those mechanical margins. This is said without any knowledge about your printer (and document settings).

Yes, but how do I do that ?

In principle, LO retrieves margins from the driver and checks them against what you set in Format>Page and warns you if you exceed what the driver says. Of course, you can ignore the warning and override the margins, i.e. setting all of them to zero, but that’s software. If printer hardware can’t print edge to edge, the document will be clipped to mechanically printing area.

It’s not so much edge to edge, it’s more the bottom of the page. I’m losing 3 lines or so at the bottom of the page where I didn’t used to.

Is the document also clipped on screen?

No it isn’t.

Printers also have mechanical top and bottom margins which are necessary to grasp the sheet and insert/extract/guide it into the engine. How wide have you defined your top and bottom margins?

By the ruler in the screenshot, the paper format selected is Letter: 6 mm wider and 18 mm shorter than A4.
Choose menu Format - Page Style - Page tab, and choose there A4.

Thank you.