Check your audio cable connections. Make sure the 3.5mm cable has been FULLY inserted into the line-in port on the Play:5. 

Change the Audio Compression setting in the Sonos app to Uncompressed for the best quality audio. You can also experiment with different Source Level settings under the Line-In settings for the Play:5.

Also be sure to remove dust and dirt from the record using an anti-static record brush like this:
https://www.amazon.com/Boundless-Audio-Record-Cleaner-Brush/dp/B071DWG4C8/

Thank you. I’ve adjusted the settings again and have got a better sound. Just wondering wether I should upgrade the stylus? 

Does the stylus look worn? It may just need to be cleaned. How old is the stylus? How long have you had the turntable and how often do you use it? If you want a little better audio quality, you could upgrade the entire cartridge.

There are multiple adjustments of the tone-arm and stylus that can impact sound. Best to get the specs for your cartridge and turntable then follow the setup steps from the manufacturer.

You can find many helpful blogs or videos too.

Two quick search results:

https://audio-technica.com.au/latest-news/how-to/align-turntable-cartridge/

https://www.theabsolutesound.com/articles/setting-up-a-phono-cartridge-1

Here is the Denon manual. Make sure that you are using the correct tracking force for your cartridge.

Almost certainly all your issues arise at the turntable/vinyl end. And if you do not enjoy deploying all the suggestions made so far, from time to time, you have to ask yourself if vinyl really is a source for you to use. Digital audio was invented to address all these and other issues that were/are inherent in the vinyl medium.