Can't upload logo file from IQR Config admin page

Technical details regarding my environment

YOURLS version: 1.9.3-dev
Plugins enabled:
1. iqrcodes/plugin.php
2. usrv/plugin.php
3. admin_issue_diagnostic/plugin.php
YOURLS DB Ver: 506
PHP version: 8.1.29
Server OS Build: Linux
Server & version: nginx/1.18.0
Browser information: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4 Safari/605.1.15
Generated by the AID Plugin ver 1.0

Logo file upload button "Choose file" does nothing when clicked.

Nothing happens. The page does not reload. There is no file dialog popup.

I have never seen it, but I assume that a file dialog box opens up in browser.

In a browser tab, navigate to https://sh.ort.url/admin/plugins.php?page=iqrcodes
On the IQRCodes Config tab in the admin options page, scroll down to section Logo Settings.
In dropdown Use Logo, select Yes
Click button Choose File below the title Upload Image.
Wait for nothing to happen.

Reloaded/refreshed the page a few times and tried clicking the button each time.
Thought it might be a browser cache issue, so tried the same in privacy mode and different browsers - Sometimes a fresh browser or privacy mode window worked. The choose file dialog opened. But this was random and many other times, it would not show up.
Enabled debugging in YOURLS config.php - not very helpful as I can't find a log file and i think the debug just prints messages on the page when it renders. Also, It only shows SQL-related messages.
Check nginx access and error logs - didn't find anything other than conflicting server names, which is a whole other issue I need to get to.