Obviously you guys can speak a bit better as to what's correct, but I'm not entirely positive that's a totally correct fix either.
TEST5, TEST4 and TEST3 are presumably 3 separate users (not 1 user with a long name). TEST5 normally being the first one in the list (in LTR). With inheriting the direction of the parent/page, that doesn't actually enforce isolation between individual names in the list, hence you see it written as "TEST5, TEST4, TEST3" despite these being separate people. If I'm correct, it should be closer to "TEST3, TEST4, TEST5".
Depending on how neutral and LTR characters are mixed here, you may get that semi-common weird order too.
It seems to me that the correct fix is to enforce independent directionality/isolation on a per name basis. I've done this now by removing the dir=auto on the wrapping element and applying <bdi> tags to the individual names that will be rendered within the phrase. This should keep the overriding phrase directionality and ensure that each name is isolated from each other. (In a browser that supports it -- Chrome or Firefox.)