The trailing slash on any QDN itself is defined by the IETF RFC 3986 Section 3 and is optional/trivial if no path is given, but authority is present:
When authority is present, the path must either be empty or begin with a slash ("/") character.
So if no path, or an empty path is given it is the same as just a trailing slash. It should not show up in Chromes addressbar.
The trailing slash also is always present if you for example copy a URL with no path from Chromes addressbar, but not visible. If you copy that URL, it suddenly has that trailing slash, while normally when you are on a sites root path with a trailing slash, it is not getting shown. Therefore: it is there but Chrome hides it.
This is a different problem from the trailing slashes.
Lets go through the redirects from non-WWW to WWW.
set your links in your DOM to the version you want (without trailing slash)
set the canonical according to the URLs you want: <link rel=canonical href=https://www.booqnly.com/contact>
set up redirects
3.1. with a PageRule https://www.booqnly.com/*/ → ( 302 ) → https://www.booqnly.com/$1
3.2. if on Cloudflare Pages with the _headers file.
3.3. with your local webserver config (nginx.conf or .htaccess) and redirect with some patternmatching.
Make sure you flush your DNS cache and restart your router & computer, this should fix that.
Make sure you use 1.1.1.1 as DNS resolver
When things are cached, they are cached but if your DNS resolver is slow or overloaded they sometimes instruct devices to cache longer, which is bad. If you use CLoudflares DNS you are on the safe side.