Fatal Error: Cannot use string offset as an array

Hello,

This error appears after updating to any version after 2.1.1.

Errors are as follows:
PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /wp-content/plugins/wp-user-avatar/includes/class-wp-user-avatar-functions.php:226

After updating there are errors that occur in two places:
1. The dashboard of the backend, where comments are displayed, instead there are multiple errors and the dashboard stops loading anything after it.
2. Comments that users leave on posts on the front end

I found that when I comment out the code on lines 226 and 227 of class-wp-user-avatar-functions.php, the errors are removed from place 1 above, and the comments are loaded on place 2 above. But while the comments are loaded in place 2, the avatar of the user appears as if they never chose one (default image).

Looking at the changelog for this plugin, I noticed the plugin developer had seen this error elsewhere and resolved it in version 2.2 but for a section a few lines down from where my error is throwing. Not in the same place, but close to it (lines 248-252)
https://pluginarchive.com/wordpress/wp-user-avatar/v/2-2-2/2-1-9.

I thought it could be my theme but I am finding the same errors when switching to the twenty twenty theme.
Error is present in the most recent wordpress core update (5.6) as well as 5.3.1 that I had updated from.

Thank you!