Trouble with Fire stick

When I go to prime or sling for a while and go back to Tablo it takes forever to reload and most of the time I have to restart the fire stick. The screen comes up black and sometimes it’s got the blue on the left side. This problem just start without any change on my end? I have no problem with roku or IPad?

You didn’t say when generation of fire stick you are using.

My gen 2 started getting the gray/black screen affect after recently being blessed by a overnight Amazon UI update. If you want to see some missing thumbnails this is the UI for you. It can take a long time for the UI screen to populate - if ever. After the inital update I had to reboot the stick before it even attempted to cleanup the UI screen.

We started out our attempt to cut the cord (oct 21) with a new fire cube for the LR tv and a 4k stick for the BR along with a fire tv recast DVR. All thought the recast worked well, the fire tv cube/stick experience was a complete disaster. Took 5+ hours to download the first updates and it when down hill from there.
You never knew what you would get when you tuned it on. Often times all blank icons, sometimes 1/2 missing. It was completely unusable at times. I called amazon tech support so many times, I lost count.
The stick was replaced, and the new one was no better. I unplugged power/HDMI/router, restarted the devices etc so many times my head was spinning. Even tried factory resets. Nothing worked. Wife was not a happy camper with my attempt to cut the cord. ( YOU ARE NOT CANCELING DIRECT TV). Not giving in, I ordered 2 Roku ultra’s and a Tablo quad OTA unit. I had them all hooked up (leaving the Fire tv stuff and Direct TV in place) , latest software installed and using within an hour,!! I finally had enough and sent the Fire TV garbage back where it came from. IMHO the Fire TV product are complete garbage when compared to the roku/Tablo set up. The new set up is still a learning curve, but we get better at using it every day.