I have a Safari Extension which replaces default new tab and puts a link on a generated new tab.
This link can be either usual URL link, or a URL Scheme, something like
plecoapi://x-callback-url/df?hw=${char}&sec=dict
In iOS 17 and previosly, this link worked flawlessly.
In iOS 18, including 18.2, this X-Callback-URL link works only once, if I kill Safari process, reopen Safari and tap the link.
Each subsequent tap will just reload the page, link won't work anymore until the next Safari reload.
Usual URL links works every time without a problem.