Qooker tap. Poor boiling water flow. Hot/Cold flow ok.

[Grey_Area]

Looking for a little guidance, as the Qooker technical support is quite poor, as in; any questions posed to them are being ignored.
Initially I thought the decreasing flow on the boiling side was probably down to a filter, so ordered the kit, cleaned out the scale, fitted my new filter and seals etc to the cyl and then tried out the tap. My expectations were not met...
It still had the reduced flow and splutter I was trying to cure.
The nozzle/spout has been descaled comprehensively, and is fine.
The hot and cold water flows are fine.
I then looked at the faq, saw they were suggesting a new prv; which for us was unlikely to be an issue, but I did as anyone would do, I gutted it. It's not needed as our pressure here is frankly dire, only around 2 bar ish.
No improvement with the prv gutted.
So PH what have any of you good folks come across that I should evaluate next?
Possible a hose with a calcium build up, I'm asking as I don't want to just force anything down a flexi hose, with the risks of damage, especially as the one leading to the tap itself is extraordinarily well hidden by an under sink installation, and if I tear it, it's going to be one hell if a job to get it all out and repaired .

TIA.

[langy]

I had this a few weeks ago and started to research what the issue was.

Fortunately for me, it seems to have sorted itself out......