S21FE slow UI

[Shamrock_Sean]

Hello, 

I recently purchased a new Galaxy S21FE 8 gig ram Snapdragon version. All was going well until charging the phone with the correct cable and a Samsung fast charger at 25w. If I want to use my phone whilst charging it starts to slow down right across the UI. Scrolling is frustratingly slow but as soon as I unplug the charger it's back to normal faster speeds. What's going on here?? I think it's ridiculous. I tried plugging in at various different wall sockets still the same. Tried different cables nothing works. If this is something Samsung is doing on purpose I want to know why?? It becomes unusable at times when plugged in. Phone is on One UI 4.1. Also randomly in some apps like maps, Facebook Messenger or Ebay the screen dims even with auto brightness off. Annoying 

[BandOfBrothers]

My Samsung Galaxy s²² Ultra 256gb Exynos SoC appears to work fine while sat on a wireless charger @Shamrock_Sean 

Not sure whats going on with yours unfortunately.

[Shamrock_Sean]

It's not a wireless charger I said wired charging

[BandOfBrothers]

I understand @Shamrock_Sean 

I added that part to explain how I charge my phone to show All works fine for me this way.