PHP warning message: Trying to access array offset on null.

Hi,

I have WordPress 6.7.1 and PHP 8.3.14, Sydney- version: 2.48 installed, and I got several warning messages with Query Monitor.

Message: Trying to access array offset on null.

Location:

• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 200
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 206
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 207
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 211
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 212
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 216
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 217
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 221
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 222
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 226
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 227
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 231
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 232
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 240
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 245
• wp-content/themes/sydney/inc/customizer/style-book/class-sydney-style-book.php on line 246

Please correct, thank you.

The page I need help with: [log in to see the link]