Input value "splashify" contains a non-scalar value.

Problem/Motivation

Website runs out of memory due to an error labeled
BadRequestHttpException: Input value "splashify" contains a non-scalar value. in Symfony\Component\HttpKernel\HttpKernel->handle()

The logs show this happens hundreds of times before i get an out of memory failure on our Drupal 10 upgraded website homepage, this doesn't happen locally on the original 9.5.11 website.

Steps to reproduce

install and configure Splashify for a popup on the homepage, configuration of page seems normal.

Proposed resolution

Fix the non-scalar value issue and correct code where we can.