Not compatible with page cache

There are some problems if page cache plugins are used:

Inline CSS for browser scrollbar width is hardcoded in output based on current browser user-agent in inc/dynamic-css/block-editor-compatibility.php at line 217:

// Detect the operating system and set the typical scrollbar width.
$user_agent       = isset( $_SERVER['HTTP_USER_AGENT'] ) ? $_SERVER['HTTP_USER_AGENT'] : '';
$scrollbar_widths = [
	'Win'     => '17px',
	'Mac'     => '15px',
	'Linux'   => '15px',
];

$scrollbar_width = '0';
foreach ( $scrollbar_widths as $platform => $width ) {
	if ( strpos( $user_agent, $platform ) !== false ) {
		$scrollbar_width = $width;
		break;
	}
}

$dynamic_css .= '
	:root {
		[...some lines removed...]
		--ast-scrollbar-width: ' . $scrollbar_width . ';
	}

A wp_get_attachment_image_attributes filter changes src attribute of header image in output based on current browser user-agent in inc/markup-extras.php line 2036:

if ( astra_check_is_ie() ) {
	// Replace header logo url to retina logo url.
	$attr['src'] = $retina_logo;
}

A get_custom_logo filter changes src attribute of header image in output based on current browser user-agent in inc/markup-extras.php line 290:

if ( astra_check_is_ie() ) {
	// Replace header logo url to retina logo url.
	$attr['src'] = $retina_logo;
}

The above used function astra_check_is_ie() can be found inc/extras.php at line 301:

/**
 * Function to check if it is Internet Explorer.
 *
 * @return true | false boolean
 */
function astra_check_is_ie() {

	$is_ie = false;

	if ( ! empty( $_SERVER['HTTP_USER_AGENT'] ) ) {
		$ua = htmlentities( sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) ), ENT_QUOTES, 'UTF-8' );  // phpcs:ignore WordPressVIPMinimum.Variables.RestrictedVariables.cache_constraints___SERVER__HTTP_USER_AGENT__ -- Need to check if its ie.
		if ( strpos( $ua, 'Trident/7.0' ) !== false ) {
			$is_ie = true;
		}
	}

	return apply_filters( 'astra_check_is_ie', $is_ie );
}

Astra 4.8.11