MACRO SQL ERROR when alert action repeats but not originally

I've got an issue where I have an alert sending a POST to a third party system for volume issues to create incidents, but I've had to do some SQL to escape the backslash in the volume name. It works fine when the alert triggers initially, but if I set it to repeat in 1 day if it is still active, the same statement throws a MACRO SQL ERROR.

Ideally we want to resend the POST in a day, to ensure that someone hasn't closed the alert in the other system but not resolved the actual problem. The retrigger will reopen the case but if the case is still open, the duplicate will be suppressed. This is preventing that behavior from being enabled.

Any thoughts on how to resolve this?

Statement in alert action configuration:

"description": " ${SQL: SELECT replace(Caption, '\', '\\') FROM Volumes WHERE VolumeID = ${VolumeID}} Percent ${N=SwisEntity;M=VolumePercentUsed} used"

Output when alert initially triggers:

"description": " H:\\ Label:New H Drive f4b7ee73 Percent 96 % used"

Output when alert triggers after 1 day:

"description": " MACRO SQL ERROR - Incorrect syntax near '{'. Percent 96 % used"