i have similar problem.
it shots when i try submit form without setup sheet-name and sheet-tab-name for that form
then I do a little investigation and find out that in file ‘./includes/class-gs-service.php‘, in public function cf7_save_to_google_sheets(), on line 83 array $form_data get this data
(
[0] => Array
(
[sheet-name] =>
[sheet-tab-name] =>
)
)
and then on line 87 we have isset() = true in this case,
so i replace isset() with !empty().
old 87 line:
if ( $submission && isset( $form_data[0]['sheet-name'] ) && isset( $form_data[0]['sheet-tab-name'] ) ) {
and new one:
if ( $submission && !empty( $form_data[0]['sheet-name'] ) && !empty( $form_data[0]['sheet-tab-name'] ) ) {
and all work perfect now