Possible ui bug

So the past few days of league ive been experiancing a few bugs my guess would be like id load in and id have no Ui or just like today in my ranked match i was killed by a gnar and my Ui just dissapeared and i couldnt get it back i couldnt even Hit escape to bring up the leaving tab to try and fix it..... i know theres somethign that u can press to hide ur ui but thats not what happend....