The Virtual Keyboard Fails Typing on My Android 9 Smartphone

Doing the very first coding exercise;
<h 1>Hello</h 1>
I was unable to edit the code. Placing the cursor at the end of “Hello” and pressing space bar duplicated the word:
<h 1>HelloHello</h 1>
I thought could be the browser. But also happened using Chrome.
I was using Swiftkey Keyboard. By switching to Simple Keyboard I was able to type all characters correctly. however, The Backspace key does not work. Meaning that I can not correct typos.
I would like to know which virtual keyboard is compatible - if someone can tell me.
I tryed with Chrome on my Windows 7 PC and everything works fine.
The problem is using my Android Pie Smartphone…

Edit:
Good news everyone. I continued testing and found out that “Hacker’s Keyboard” works perfectly.
Thanks to all.

for you and everyone else that may have the same issue, there is this article with some suggested keyboards: