Translation of a node only is showed when a specific language is selected

I have encountered a problem with translation. When I try to translate a custom field of a custom node type it overwrites the original value.

Here is how it looks like

The custom field

https://i.stack.imgur.com/dN5rM.png

I create a node and enter following information

https://i.stack.imgur.com/v0IyN.png

Then I click Save, the node appears, so far so good.

Next I click Translate

https://i.stack.imgur.com/jVORi.png

I can see that translation not available now, click Add

https://i.stack.imgur.com/u2PYe.png

Then I have the following url link

/node/8/translations/add/en/
Enter the following value

https://i.stack.imgur.com/201X2.png

Now I have two nodes.

https://i.stack.imgur.com/2fyKd.png

Let go to the original node and see what is the value of the field.

https://i.stack.imgur.com/DxhHI.png

It is the same as it was before, but on the web page, I have two nodes with different translations.

The interesting thing that both of the two nodes in admin panel have the same translation as currently selected language, even if I click the edit button from the Translate tab, I need to switch the language via a switcher for example to get the content of a node for the selected language.

And that makes me crazy, I cannot understand what is going on really, how can I edit a translation of a node without changing the language ?

Please help me to solve this problem, I am completely lost with this stuff.

P.S.

Database entries are added correctly I guess

https://i.stack.imgur.com/FHinV.png