When dealing with technicals be technical and communicate specifics like actually inspectable urls so others can SEE and reproduce the problem or errors codes.
Make sure on desktop when you hover over a link that it is actually pointing to the proper url, if not adjust your admins navigation settings to update the menus.
Check your admin to inspect redirects, DO NOT DELETE REDIRECTS arbitrarily
https://help.shopify.com/en/manual/online-store/menus-and-links/url-redirect
If redirects possibly related to collections are found make 200% sure you know why those redirects exist and who added them and why.
If still not solved disable javascript in your browser and check again, if the redirects stop happening then somewhere in either the theme code or from an app javascript is redirecting the page. On chrome browser with javascript disable open devtools(F12 or ctrl+shift+i) then press ctrl+shift+f to open search and look for “window.location” or simlar javascript based redirects.
https://developer.chrome.com/docs/devtools/search/
If javascript being disabled does not stop redirects then view the source.
Visit a collection url by entering in the browser url bar directly NOT clikcing a link on the page such as a menu item.
press ctrl+u view source - If still being redirected check the page source by trying to quickly view the source of the page the moment you enter the url by pressing ctrl+u on a desktop browser. When the view source tab is open modify the view-source’s tab url if need be to get to the initial collection url.
Look/find(ctrl+f) for any meta-refresh tags in the htmls
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta#attr-http-equiv
Then look/find(ctrl+f) for any javascript like window.location
https://stackoverflow.com/questions/503093/how-do-i-redirect-to-another-webpage
If still not found someone probably needs to step through the theme as it loads javascript to find redirects as javascript loads other javascript.