Mistake in the Qunut of Witr Salah

Assalamu Alaykum
Respected Mufti Sahib

I had for about close to 5 or 6 yrs read my witr Salah with a mistake in one word. Unknowingly I ended up thinking that was the way to read it and continued like that, not realising my mistake until a few yrs into the Alim course. I was reading wa nakhfidu (و نخفد) rather than wa nahfidu (و نحفد). Firstly, I wasn’t particular regarding the d sound at the end whether it was ض or د . I wasn’t to sure and continued reading it not too sure, in between. But the bigger issue is that I was reading khaa instead of Haa. Then I came across a quotation in اللباب (Al Lubab Sharh of Quduri). Under the Chapter of Sifatus Salah, under the mention of witr, in the Sharh al Lubab it comes regarding wa nahfidu: و لو أتى بها معجمة فسدت كما في الخانية.

This seems to me to mean if the daal at the end is made into a dhaal and not referring to my mistake
But please check this Ibarah and regarding the mistake I was making and please advise whether that would have rendered my saalah invalid or not
And whether I will have to make Qadha of all of that or not. Really appreciate Mufti Sahib.
Jazakallah Khair