The module introduces new configs to the views, but doesn't declare a config schema for it.
Install the Configuration Inspector module → and run the following on an affected views config.
drush config:inspect views.view.events --detail
-------------------------------------------------------------------------------------------------------------------------------------------- ---------------- ------------- ------
Key Status Validatable Data
-------------------------------------------------------------------------------------------------------------------------------------------- ---------------- ------------- ------
views.view.events:display.default.display_options.exposed_form.options.bef.filter.combine.options_show_only_used missing schema
views.view.events:display.default.display_options.exposed_form.options.bef.filter.combine.options_show_only_used_filtered missing schema
views.view.events:display.default.display_options.exposed_form.options.bef.filter.combine.options_hide_when_empty missing schema
Add config schema.
N/A
Fixed
3.0
Code
Issue #3385927: Add missing config schema for new configurations...