New modem---no printer

Just added new modem, now I cannot print anything in the LibreOffice format. Printer just will not print. It prints okay with PDF documents and other formats but will not print anything in the Libre format.
It printed fine with my lower speed modem.

By modem, I assume you mean your WiFi as well. Maybe best to restart LO first. Your printer might have a new path or IP address, LO should be able to print to it if your operating system has recognised/installed it. Your system might have created a duplicate printer and LO might still look for the old printer if you want to print a document that was printed previously. In that case when you want to print, press Ctrl+P to open the print dialog window. On the right hand side of that is a tab labelled General select that. At the top is a heading Printer and below is a printer listed, click on the drop down arrow next to the printer to select the other printer with a similar name. OK to print.

To remove duplicate printers and set default printer please follow your operating system instructions/ printer manual

Thanks Earnest. I tried all of the above and nothing seemed to help. Everytime I tried printing in LO, I got—‘cannot connect to the printer’, even though I was connected . Finally deleted the printer altogether and reinstalled. Had the same problem again, but I noticed this time that it gave me the option of 2 different printers. When I checked the option for the printer that I just installed, it printed. Thanks again for your help.