Yes, I can confirm this behaviour. It is more or less "by intention", although I can see that this may result in unwanted behaviour.
The reason is that TAS snap keys act just like pressing or releasing two keys at the same time (snap key + direction key). So, when pressing, for example, "TAS snap left", the bits for "snap" and "left" are set for player actions. When pressing "TAS snap up" now (while still holding the first TAS snap key pressed), the bits for "snap" and "up" are set (while the bit for "snap" is already yet). All fine so far. Now, one of the two TAS snap keys is released. This will cause the bits for "snap" and one of the directions to be unset. But there is still another direction bit set now, with no snap bit set -- this is now a simple direction action, and the player will move accordingly!
When pressing TAS snap keys very fast, it may therefore happen that two TAS snap keys will be in "pressed down" state at the same time, causing the above problem when releasing one of them without releasing the other(s) at the exact same time.
This could probably be fixed by storing which TAS snap buttons are currently pressed (instead of just setting and unsetting the corresponding bits in the player actions).
There already exists topic just about that
This was a different problem (well, bug), which resulted in sometimes moving the player while only pressing and releasing one single TAS snap key very fast, which cannot happen (anymore) in the above scenario.