WorldEdit version: Worldedit-bukkit-7.1.0
Platform version: Spigot Paper 1.16.3

Copy and paste a line of furnaces will place the furnaces not as the original

To Reproduce

1. place a line of furnaces and select, copy this.
2. at another postition (few blocks away) paste the copied furnaces and you will see the furnaces are turned arround.

Screenshots

Update worldedit to version 7.2 since 7.1 is outdated

7.2 is not a R version but RC. I downloaded the latest version and that is the 7.1 but i will give it a try to see if the 7.2 version solves the problem.

Sorry me bad, 7.2 RC version did solve the problem. My apologies for this