Kivy TextInput CheckBox communication

I have a couple of TextInputs with a Checkbox next to them. I want to tab through them (press Tab > go to next Textinput without checking Checkbox. Enter value and press Enter > go to next Textinput and check Checkbox). This all works by setting up this definition of TextInput:

<TextInput>:
    multiline: False
    size_hint_x: None
    padding_y: [self.height / 2.0 - (self.line_height / 2.0) * len(self._lines), 0] #centers middle
    halign: 'center'
    write_tab: False
    input_type: 'number'
    input_filter: 'int'

Additionally i have done some things like only allow number input and centering the text, as you can see. My actual CheckBoxes and TextInputs look like this:

            CheckBox:
                id: gre3
                on_active: root.change_gain(*args, gre3Val.text)
            TextInput:
                id: gre3Val
                hint_text: 'Green #4 Gain [%]'
                on_text_validate: 
                    gre3.trigger_action() if self.text != '' else 0
                    red4Val.focus = True if self.text != '' else 0

from which i call this function:

    def change_gain(self, *argv):

        checkBox = self.getID(argv[0]) #this simply returns the actual id of the object
        checkBoxValue = argv[1] #True/False
        gainValue = argv[2] #int

        if int(gainValue) >= 100:
            gainValue = 100
            tempObj = checkBox + 'Val'
            self.ids[tempObj].text = '100'
        # if color == 'red':
        #     print('Not yet implemented')
        #     #change_laser(s, )
        print(checkBox)
        print(checkBoxValue)
        print(gainValue)

        if checkBox[0:3] == 'red':
            tempColor = 'Red'
        elif checkBox[0:3] == 'gre':
            tempColor = 'Green'
        else:
            tempColor = 'Blue'

        tempNo = int(checkBox[3])

        if checkBoxValue:
            self.statusText = tempColor + ' #' + str(tempNo+1) + ' enabled ' + '(' + str(gainValue) + ' %)'
        else:
            self.statusText = tempColor + ' #' + str(tempNo+1) + ' disabled'

The function isnt finished yet. However, what you can see is that i limited the input to 100. Now my problem is: When im in the TextInput field which is linked to an already checked Checkbox and update the value, the checkbox gets unchecked because of the way i link the both widgets (checkboxName.trigger_action()). Is there a better way for this, so i both call the linked action of the checkbox and check it?