2 hopefully helpful pieces of info:

- Short trades close at the ask, not the bid. So your setting spread to whatever value cannot have an effect.

- Lifetime lets the trade exit at next open, not at current close. So you were probably comparing the wrong prices.

Still, I cannot see how that exit price comes together, unless that was live. Then ask the broker. Otherwise, if you think something is wrong with it, contact support with the script and data for reproducing it, and we'll help.

And finally please post topics to the suited forum. This makes life easier. Questions go in the starting forum, bug reports in the bugs forum, neither of them belongs in the future forum.