Mail template gets modified

Sorry if I am misunderstanding but is this fix supposed to be included in the current version 1.4.0?
Because if it is, I am still facing the issue that the e-mail template isn’t being saved to the database. Even though InvoicePlane reports ‘Record successfully updated’.

Here is a link to the closed topic including the e-mail template I’m trying to use: https://community2.invoiceplane.com/t/duplicate-e-mail-template-parser-editor-injection/838