First, make sure the condition is checked on the conditions tab of the task so it will be applied to the task.
If I'm reading things right, in the condition you are comparing {USERVAR(LastDayOfTheMonth)} (which is "4/30/2022") to a regular expression of "30".
Since you really want to compare today to {USERVAR(LastDayOfTheMonth)}, I believe you can simplify this by changing the condition to equal and set
value1 to {USERVAR(Date)} and Value2 to {USERVAR(LastDayOfTheMonth)}. Test by setting Value2 to "4/13/2022" to trigger last day of the month processing. This uses the date formats you have already in your user variables.
Using "regex-match" as the condition means using a regular expression in value2 to see if it matches value1. i.e. if "4/30/2022" were in value1 then a regular expression of "\d{1,2}/30/\d{4}" would match.
one but not more than 2 digits followed by a slash then then number 30 then a slash then 4 digits.