I'm new to the online game but when this happens on the PC I believe it's due to the "more baserunning decisions" option, which is apparently active online as well: https://stratomatic365.fandom.com/wiki/Maximum_Rules
That is an example of a max rules option that probably should not be selected in the online game. More Baserunning Decisions is meant for the face-to-face (or face to computer) player--not for HAL.
Another black box-ism that in this case makes SINGLE** results uncertain. It probably doesn't come up much, but it shouldn't come up at all.