Varios errores

Hola,

de un día para el otro me saltan varios errores tanto en la sección de wp-admin como en la página accesible para todo el mundo. Probé con desactivar todos los plugins y me siguen saliendo. Veo bastante lo de string is deprecated en casi todas.
La verdad es que me veo superado ya que no logro entender cuál es el motivo más allá de un fallo al actualizar wordpress.
Simplemente quería saber si es posible remediar esto.

Dejo algunos de los errores que me saltan, este con woocomerce activado:
Deprecated: strstr(): Passing null to parameter #1 ($haystack) of type string is deprecated in /hosting/www/deicacreacions.com/public/wp-content/plugins/woocommerce/includes/wc-page-functions.php on line 139 Deprecated: strstr(): Passing null to parameter #1 ($haystack) of type string is deprecated in /hosting/www/deicacreacions.com/public/wp-content/plugins/woocommerce/includes/wc-page-functions.php on line 139 Deprecated: strstr(): Passing null to parameter #1 ($haystack) of type string is deprecated in /hosting/www/deicacreacions.com/public/wp-content/plugins/woocommerce/includes/wc-page-functions.php on line 139 Deprecated: strstr(): Passing null to parameter #1 ($haystack) of type string is deprecated in /hosting/www/deicacreacions.com/public/wp-content/plugins/woocommerce/includes/wc-page-functions.php on line 139 Deprecated: strstr(): Passing null to parameter #1 ($haystack) of type string is deprecated in /hosting/www/deicacreacions.com/public/wp-content/plugins/woocommerce/includes/wc-page-functions.php on line 139 Deprecated: strstr(): Passing null to parameter #1 ($haystack) of type string is deprecated in /hosting/www/deicacreacions.com/public/wp-content/plugins/woocommerce/includes/wc-page-functions.php on line 139 Deprecated: strstr(): Passing null to parameter #1 ($haystack) of type string is deprecated in /hosting/www/deicacreacions.com/public/wp-content/plugins/woocommerce/includes/wc-page-functions.php on line 139

Este sin plugins activados en la sección wp-admin:

Deprecated: Return type of Requests_Cookie_Jar::offsetExists($key) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Cookie/Jar.php on line 63 Deprecated: Return type of Requests_Cookie_Jar::offsetGet($key) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Cookie/Jar.php on line 73 Deprecated: Return type of Requests_Cookie_Jar::offsetSet($key, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Cookie/Jar.php on line 89 Deprecated: Return type of Requests_Cookie_Jar::offsetUnset($key) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Cookie/Jar.php on line 102 Deprecated: Return type of Requests_Cookie_Jar::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Cookie/Jar.php on line 111 Deprecated: Return type of Requests_Utility_CaseInsensitiveDictionary::offsetExists($key) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Utility/CaseInsensitiveDictionary.php on line 40 Deprecated: Return type of Requests_Utility_CaseInsensitiveDictionary::offsetGet($key) should either be compatible with ArrayAccess::offsetGet(mixed $offset): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Utility/CaseInsensitiveDictionary.php on line 51 Deprecated: Return type of Requests_Utility_CaseInsensitiveDictionary::offsetSet($key, $value) should either be compatible with ArrayAccess::offsetSet(mixed $offset, mixed $value): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Utility/CaseInsensitiveDictionary.php on line 68 Deprecated: Return type of Requests_Utility_CaseInsensitiveDictionary::offsetUnset($key) should either be compatible with ArrayAccess::offsetUnset(mixed $offset): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Utility/CaseInsensitiveDictionary.php on line 82 Deprecated: Return type of Requests_Utility_CaseInsensitiveDictionary::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /hosting/www/deicacreacions.com/public/wp-includes/Requests/Utility/CaseInsensitiveDictionary.php on line 91

Ninguno de los errores impide el funcionamiento de la web pero son muy molestos.

Gracias por vuestra ayuda

La página con la que necesito ayuda: [accede para ver el enlace]