Another drain backing up!

Every time we do laundry the water backsup & out over the drain.
The vertical pipe is about 4ft off the floor & drains into its own dry well..

This has been this way for years no changes or additions.

This new drainage problem has started I would say in the past 6 months
It would happen every so often but no its every time we try to do laundry.

The pipe is clear/no blockage.. When the water drains it seems like air is pushing
It back out the top of the drain instead of letting the water go down into the well.

Any ideas for fixing this problem?

Thank You Steph ~