Have you checked the oil, using the correct method & preferably after a reasonable ryde?? The SE5's are very dependent on the oil level, and it's not uncommon to find that 'dealers' have somehow screwed up getting the oil change quantity correct!! So your first step
REALLY should be to take your Spyder out for a ryde, saaay 20 mins or so, then stop & check the oil level! If it's too low
OR if it's overfilled, then that could well be your problem....
That said, oil level gear change issues are
USUALLY 'selection' issues, causing difficulties selecting gears either way, up or down; and
especially when trying to select either first or reverse from neutral.... so maybe your problem is something else?! If it's not the oil level or maybe if they've used the wrong oil, cos you REALLY need to use oil suitable for motorcycle wet clutches in these things - using anything else can cause.... wait for it..... shifting issues &/or clutch slip!!
The only fix for the latter there is to change the oil.... again!
Anyhow, if it's not the oil level or oil type, it might pay to get down on the ground alongside the LHS of the Spyder & look underneath the tupperware at the trans case just inboard of the riders LH Foot plate to check that the selector arm is properly seated & secured on the shaft sticking out of the side of the box. If it is fixed properly & not flopping around, then any other problems are likely to be electrical or internal, and likely require a visit to your dealer. Sorry!
Good Luck!