Problem with upgrade to PHP 8.1

I’m checking the possibility for an upgrade of my homepage from PHP 7.4 to 8.1

All on Apache server, Theme: Twenty Sixteen:

In a separate, new created online testing environment an upgrade from PHP 7.4 to 8.1 works with OMGF active. (But only there!)

In two local staging environments (Laragon + Local) an upgrade to PHP 8.0 or 8.1 results in an error (domain removed from log-lines):

Warning: Array to string conversion in \wp-includes\formatting.php on line 1098

> {main}( )
> require_once( \wp-admin\admin.php )
> require_once( \wp-load.php )
> require_once( \wp-config.php )
> require_once( \wp-settings.php )
> include_once( \wp-content\plugins\host-webfonts-local\host-webfonts-local.php )
> omgf_init( )
> OMGF->__construct( )
> OMGF->define_constants( )
> OMGF->esc_array( $array = ['merriweather' => ['subset_family' => 'Merriweather', 'subset_font' => 'merriweather', 'available_subsets' => [...], 'selected_subsets' => [...], 'used_styles' => [...]], 'montserrat' => ['subset_family' => 'Montserrat', 'subset_font' => 'montserrat', 'available_subsets' => [...], 'selected_subsets' => [...], 'used_styles' => [...]], 'inconsolata' => ['subset_family' => 'Inconsolata', 'subset_font' => 'inconsolata', 'available_subsets' => [...], 'selected_subsets' => [...], 'used_styles' => [...]]] )
> esc_attr( $text = [‘subset_family’ => ‘Montserrat’, ‘subset_font’ => ‘montserrat’, ‘available_subsets’ => [0 => ‘latin’, 1 => ‘latin-ext’], ‘selected_subsets’ => [0 => ‘latin’, 1 => ‘latin-ext’], ‘used_styles’ => [0 => ‘400’, 1 => ‘700’]] )
> wp_check_invalid_utf8( $string = [‘subset_family’ => ‘Montserrat’, ‘subset_font’ => ‘montserrat’, ‘available_subsets’ => [0 => ‘latin’, 1 => ‘latin-ext’], ‘selected_subsets’ => [0 => ‘latin’, 1 => ‘latin-ext’], ‘used_styles’ => [0 => ‘400’, 1 => ‘700’]], $strip = ??? )

I don’t know how to resolve this problem.