Store Locator Plus for WordPress users should skip version 4.9.11 of the base plugin (Store Locator Plus) update. Installing that release will reset some settings for the plugin including the layout settings for users that have the Experience add on.
The problem has been located and is patched in the 4.9.12 release that was published moments ago.
If you updated to 4.9.11 you will need to restore your SLP settings from a backup of the site made prior to the SLP 4.9.11 update.
Selective Restore of Settings
Experienced users can restore the following two entries from the wp_options table from a prior backup of the site if you do not wish to do a full site restore:
option_names: csl-slplus-options and csl-slplus-options_nojs
If you are not sure how to restore select options from the wp_options table your best alternative is a standard full site restore.
No locations are lost/changed during this process. They are stored in a separate location.
For Users With No Custom Layouts
If you updated to 4.9.11 of Store Locator Plus but are not using the Experience add on you may be able to update to SLP 4.9.12 and restore standard styling by doing to Settings > View > Gallery Styles and selecting one of our default styles for your site. If you were using the Default style select Default With Font Tweaks , activate it, then select Default to re-load the layout controls from our servers.
MySLP Managed Service
Most users were not impacted by this bug. The select few users there were impacted by the 18.0320 update last week have had their prior settings restored.
If you are using MySLP and think your settings were changed and your account was not reset, please let us know within 30 days so we can manually recover your prior settings.