Syndra Movement + Ultimate Bug

Hi everybody. First my english kinda sucks sorry for that :D Bug: Just walked around with Syndra and i saw that her Movement is like she turns in slowmotion (Snowday Syndra Skin) If you try this to see what i mean, skill and use Q, then click in front of Syndra and then back of her 3-4 times and she will turn in slowmotion. Found a Video on Youtube from a long time ago, think ist Season 4 but î got the Problem in Season 5 patch 5.24. Second Syndra Bug: After using her Ultimate (R) she laggs around 5-10 sec. (I tried it with Snowday Skin and without, still the same thing) Its definetly not my PC or my Internet. (PC: Intel Core i7 4790K, Nvidia Geforce GTX 970) (Internet: 100k) I checked it many times from different PCs. (My location is switzerland) It would be very nice if you could check that and fix it. I love to play Syndra but not like this :(