Clicking on this seems to go to the Forum listing for me ...

So it does!

Hmm...

It works for me on an iPhone with Safari, Chrome, and Firefox. But mobile browsers are odd, they love to aggressively cache content. Try clearing the browser cache, and if that doesn't work, I would need more information about your setup -- click here and copy/paste the result.

Here's FFox and Chrome; Android 12 and Android 11

Browser is Mozilla/5.0 (Android 12; Mobile; rv:94.0) Gecko/94.0 Firefox/94.0
Mobile: true
Tablet: false
Capability: A
Ad blocker: false (next check on 12-06-2021 @ 06:28pm)
Do not track: true
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8

and

Browser is Mozilla/5.0 (Linux; Android 12; Pixel 6 Pro) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.74 Mobile Safari/537.36
Mobile: true
Tablet: false
Capability: A
Ad blocker: false
Do not track: true
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9

and

Browser is Mozilla/5.0 (Android 11; Mobile; rv:94.0) Gecko/94.0 Firefox/94.0
Mobile: true
Tablet: false
Capability: A
Ad blocker: true (next check on 11-12-2021 @ 11:16am)
Do not track: true
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8

and

Browser is Mozilla/5.0 (Linux; Android 11; Pixel 2 XL) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.74 Mobile Safari/537.36
Mobile: true
Tablet: false
Capability: A
Ad blocker: false
Do not track: true
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9

Weird. The main difference I see is Android. I'll try other devices. Here's mine.

Safari

Browser is Mozilla/5.0 (iPhone; CPU iPhone OS 15_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.1 Mobile/15E148 Safari/604.1
Mobile: true
Tablet: false
Capability: A
Ad blocker: false
Do not track: false
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Chrome

Browser is Mozilla/5.0 (iPhone; CPU iPhone OS 15_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/95.0.4638.50 Mobile/15E148 Safari/604.1
Mobile: true
Tablet: false
Capability: A
Ad blocker: false
Do not track: false
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

PS to add: I assume this direct search link works, right?

Yep, that works.

Here is what I get when I long-press the search button on Android:

Does a quick tap work as expected?

The long press worked correctly for me on Safari, Chrome, Firefox, and Opera. At this point, I'm inclined to blame Android. My guess is it's stripping off the "search.php" for some reason, probably because the search.php isn't under the /forums/ URI; I'm sure some developer thought it would be helpful.

PS to add: I'll try changing the link to search.php with /forums/ included; it's mapped to the same thing anyway. Maybe that will appease Android.

Works now ... just has to propagate I think.

Well, more accurately, I provided a workaround for what appears by all evidence to be an Android bug. Glad it's resolved.

Still broke on mine, but I haven't cleared cache yet.

Browser is Mozilla/5.0 (Linux; Android 9; SM-G955U) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.74 Mobile Safari/537.36
Mobile: true
Tablet: false
Capability: A
Android: true
Ad blocker: false
Do not track: false
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9

**Edit**
Cleared cache, still very much points to forums...