Q.Olive Tree
Moved olive tree cutting that we grow in plastic tub for five years. Recently moved from tub due to constant waterlogged, two weeks ago. April 2020. This week it turned its leaves brown and dropped a few. Welcome your feedback and advise. Thank you

Certified GKH Gardening Expert
Unfortunately, your photo did not come through. It does sound like the waterlogged soil has caught up with the plant, though.
The transplant is added stress, and may have been caught just a little too late. Infection has likely taken over, and the plant is also experiencing transplant shock.
I would make an attempt to treat with a fungicide or bactericide. These articles will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/special/organic/biofungicide-information.htm
https://www.gardeningknowhow.com/garden-how-to/info/homemade-fungicide.htm
https://www.gardeningknowhow.com/garden-how-to/info/applying-bactericide-to-plants.htm
Make sure to allow the soil to dry out thoroughly between watering, and make sure there are drainage holes in container to allow all extra water to leave.
Here is an article that will help you to care for the tree:
https://www.gardeningknowhow.com/edible/fruits/olive/growing-olive-trees-in-containers.htm