BobJax

How big is your document/PDF? What version of Windows? Does your PC meet specs? https://affinity.serif.com/en-us/publisher/desktop/full-feature-list/
What colour space are you working in? How are you exporting? How are you viewing your PDF? Are you printing from the PDF? What type of printer? Does the printer profile match your document Colour Format? I ask these questions for basic troubleshooting.
My experience with this beta is somewhat different. I created a trifold brochure in Publisher 1.7.0.206 on a vintage 2009 Mac Pro running OS 10.11.6 with a calibrated 22" Dell monitor. In the Document setup, Colour Format is CMYK/8, Colour Profile is U.S. Web Coated (SWOP) v2. On Export, I selected PDF for Print, Raster DPI 300. I have created seven versions, all saved as PDF with no problem. The PDFs were sent to a local shop and printed on coated stock. Publish has performed flawlessly. The laser printed colour proofs were colour accurate. I am not a designer by trade, but occasionally produce print material for clients and organizations I volunteer with. 

Came here to say hello!
My name is Jane, I'm a CG artist and an amateur photographer, yet you can call me another refugee (since I've used Adobe soft previously). But I've started to look for other options and my friends recommended me Affinity. 
Also, thanks to creators for such a wonderful opportunity. 

Yes, it also says" an attempt to capture the strength and clarity of Comic Sans without the comic book associations." Comic sans is one of the most picked on fonts but is a great font for many young readers. The line I dislike the most is "Comic Sans without the comic book associations" . A young reader doesn't think, "Oh great, Lexie Readable doesn't have comic book associations." Just don't use Comic Sans as your Annual Report font.

I see that the page for Lexie Readable on DaFont.com describes it as ‘Comic Sans for the grown-ups’.

It was Lexie Readable by Keith Bates. It was interesting to email back and forth to the font creator with questions.  Sometimes I think the best Dyslexic font is Comic Sans, for Kid's books. The studies don't confirm much. Once you start making claims that a book is prepared for a Dyslexic reader an author can get slammed if the font doesn't help. A book written in OpenDyslexic got a bad review on Amazon for that reason. I did a lot of other things besides the font to try to get it right. I am not dyslexic so had to do a lot of research.

Thanks for all the helpful replies!
I bought a font recently for dyslexic versions of two books.  The big issue about some fonts is that a print license can be very reasonable, but if you use that same font for an e-book watch out. It can require a totally different license and the price goes way up. 
There is a certain style of font I need for children's books. I see many bundles of "commerical licensed" fonts on hungryjpeg.com
But there is a bundle on their sister site. Fifty (50) fonts like I need for $14, with a full commercial license. But the deal will be over in 4 days. Many of the fonts in the bundle sell individually for $9-$12. Sometimes they offer a deal from one foundry for a few days for cheap. But I haven't seen many font bundles that has what I need.
I really like the way Affinity Publish works with fonts, so I will probably get that bundle.
https://craftbundles.com/bundle/88121-the-salt-and-pepper-fonts-bundle/
Alfred, Thanks for the link. I followed the link and the fonts are nicely displayed. I found the difference between the publishing software I was testing and the site is that the software automatically installs the font, saving a few steps. 
Fixx, Good site. Thanks
Thanks for all of the comments!!
 

So it would seem! When I followed your link, I saw this:
If you like, you can go to GitHub and download the entire current Google Fonts collection as a zip archive. Alternatively, you can sync the collection with git, allowing you to update by only fetching what has changed. There’s more information about that here: https://github.com/google/fonts

Have you tried FontBase? I think it supplies access to Google Fonts. https://fontba.se/

my 2 ¢.
Fonts for free will end in tears.

Likely it was an Xara product. But it doesn't give access to all Google fonts. But as you can simply go to Google fonts at anytime and download what you want I don't really see the rush. 

I have a major book project which will involve creating 50 book versions at once, times 8 books. I have decided to wait for Affinity Publisher. Not complicated stuff-- a large illustration and two text boxes per page, saved to a PDF for printing.