The Samsung driver is working great for me, however, there is one big caveat which I encountered when printing a large PDF document: Turns out that the page content gets shifted more and more. The first page is fine, but on subsequent pages, the content gets shifted to the upper right. This increases from page to page and is very obvious on the last page of a 20-pages document. I'm attaching a photo that illustrates the problem.
My printer is a Samsung CLP-510N, connected via Ethernet to an Ubuntu 20.04 server running CUPS 2.3.1. It is shared, so macOS and iOS devices can print via Bonjour/AirPrint. I have installed suld-driver-4.00.39.
I encountered this problem when printing from Preview on macOS Catalina. I didn't get a chance to try printing from other clients, such as Windows, but can arrange that if it helps to narrow down the problem.
Interestingly, this doesn't happen if I print the pages individually from the same PDF.
Usually I recommend the most recent driver version that works with a printer, but in this case it might be worth trying 4.00.35 or 3.00.90 in case this is an obscure bug introduced in 4.00.39. If not, and if this only happens with pdf files, another option might be to use a tool such as pdf2ps to convert the pdf to postscript before printing. If neither of those helps, it may be a bug in the way the new CUPS is interacting with the driver. In that case, your best bet is probably to just print 1 page at a time.