When placing Redstone, then 1 block higher another Redstone, they connect, right?

And when you place a block on top of the first Redstone the connection gets "cut"

But when this block is dirt and becoming Farmland or wet (Not sure which one or both) then the the connection is established again. Visually only the below block looks like it connects to the next upper block, but the Redstone on the second block doesn't connect visually.

When braking the farmland and replacing with normal dirt the connection gets blocked again.

This is creating a loop with my repeaters that should only amplify the signal.

Edit: Since i could add the screenshots.

1 Picture:

You see the Redstone left from the Repeater is connecting to the upper block (And receiving power)

2 Picture:

The other side, the Redstone near the Piston doesn't connect to the Redstone below but it gives power. (Somehow)

3 Picture:

Farmland removed from top

4 Picture:

Redstone loop gets cut again.

My guess is that the block update somehow causes the Redstone to connect in a weird way.