I noticed in zsh when tab autocompleting text is getting kept around for some reason. This didn't use to happen in xterm so not entirely sure what caused it.

To figure out what's happening you can enable debug mode via term.setOption('debug', true) and then inspect the instructions that are sent from zsh when you hit tab, backspace, etc.
Typing cd[tab] yields the following:

The first 9 lines are typing c and d.

This looks to be resolved now
I actually repro'd it in an external terminal at some point, so I think it was a problem with zsh.
@npezza93 maybe caused by you locale, my remote locale is en_GB but local locale is zh_CN, and it's occurred, i changed the local locale as en_GB, its running well.