[help] the problem that the soft keyboard cannot be ejected by focus () under specific conditions when Cordova InAppBrowser-based APP is running in iPad

make an APP, with InAppBrowser with Angular5.2.9 + Ionic3.2 + Ionic Native 4.5.3 + Cordova8.0 + Cordova-ios 4.5.4 + Cordova-plugin-inappbrowser 2.0.3-dev. Access the following html, in APP and the code is as follows:

testsoftkeyboard3.html

1input1iPadiOS

2input1onblurabcalert

3input1input1

23input1:
1input2
2

currently follow mode 1, there is no problem, step 3 can be presented as expected.
but when using method 2, when calling the focus () method to let input1 get focus, the soft keyboard will flash (after it appears, it immediately disappears). Many methods have been tried to keep the soft keyboard appearing all the time. I haven"t done it for 3 days after investigating 2Jing. I don"t know if I need to modify the Objective-C code of InAppBrowser. Please take a look at how to solve it. Thank you very much!