Calling Merge::key() with an array is removed in Drupal 11; cron crashes

Hi,
I believe I am running into the same issue.
After installing Simpleads three days ago cron stopped working.
The errors I get are:

TypeError: Cannot access offset of type array on array in Drupal\Core\Database\Query\Merge->key() (line 331 of ******************/core/lib/Drupal/Core/Database/Query/Merge.php)
#0 ******************/modules/contrib/simpleads/src/SimpleAdsCron.php(96): Drupal\Core\Database\Query\Merge->key()
#1 ******************/modules/contrib/simpleads/src/SimpleAdsCron.php(79): Drupal\simpleads\SimpleAdsCron->runAggregation()
#2 ******************/modules/contrib/simpleads/simpleads.module(69): Drupal\simpleads\SimpleAdsCron->init()
#3 ******************/core/lib/Drupal/Core/Cron.php(275): simpleads_cron()
#4 ******************/core/lib/Drupal/Core/Extension/ModuleHandler.php(307): Drupal\Core\Cron->Drupal\Core\{closure}()
#5 ******************/core/lib/Drupal/Core/Cron.php(258): Drupal\Core\Extension\ModuleHandler->invokeAllWith()
#6 ******************/core/lib/Drupal/Core/Cron.php(97): Drupal\Core\Cron->invokeCronHandlers()
#7 ******************/core/lib/Drupal/Core/ProxyClass/Cron.php(75): Drupal\Core\Cron->run()
#8 ******************/core/modules/automated_cron/src/EventSubscriber/AutomatedCron.php(65): Drupal\Core\ProxyClass\Cron->run()
#9 ******************/vendor/symfony/event-dispatcher/EventDispatcher.php(246): Drupal\automated_cron\EventSubscriber\AutomatedCron->onTerminate()
#10 ******************/vendor/symfony/event-dispatcher/EventDispatcher.php(206): Symfony\Component\EventDispatcher\EventDispatcher::Symfony\Component\EventDispatcher\{closure}()
#11 ******************/vendor/symfony/event-dispatcher/EventDispatcher.php(56): Symfony\Component\EventDispatcher\EventDispatcher->callListeners()
#12 ******************/vendor/symfony/http-kernel/HttpKernel.php(114): Symfony\Component\EventDispatcher\EventDispatcher->dispatch()
#13 ******************/core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(63): Symfony\Component\HttpKernel\HttpKernel->terminate()
#14 ******************/core/lib/Drupal/Core/DrupalKernel.php(683): Drupal\Core\StackMiddleware\StackedHttpKernel->terminate()
#15 ******************/index.php(22): Drupal\Core\DrupalKernel->terminate()
#16 {main}

I was wondering if there is already a solution to this problem?
Greetings,
Rob

@robbnl: Apply the merge request above and test. If it fixes the problem, maybe mark this Review and Tested by the Community?

Reviewed and tested. The patch works. Thank you @robbnl!

Views Natural Sort 🐛 TypeError: Cannot access offset of type array on array in Drupal\Core\Database\Query\Merge->key() (line 331 of core/lib/Drupal/Core/Database/Query/Merge.php). Active and a host of other contrib modules have suffered this.