Numericentryfield can only enter once if spinner is disabled

I am using a numeric entry field on the view, if the spinner is disabled, I can enter the value for the first time, but I won't be able to click on the entry field to change the value again unless I click on the other component on the page, then I can come back to change value again.

Is it consider as a bug?

If the spinner is enabled, I can change the values without shifting focus.
I cannot change the spinner size, if the entry is configured too small, the entry box will shift local on the view when the spinner is displayed.
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