The dial by phone feature stopped working in a recent update to Store Locator Plus®. This impacted both the self-managed WordPress plugins as well as our fully managed My Store Locator Plus® service users.
The patch is available in the Experience add on version 4.9.22 for WordPress users; WordPress plugin users will need to download and install the latest release. MySLP users already have the updated software and will have the dialing feature back online by the time they read this.
Dial By Phone is a feature that wraps the phone number links in the location lists in a link with a de-facto standard tel: prefix. For users visiting your site from a mobile phone the on-phone browser will automatically dial the number when a user clicks the link.