That personel jump is pretty big, it crossed 300k and then was closing in on 310k. Seems like a big jump, especially given the UKs numbers only corssed 300k this week.
Since the Russian attack on Avdiivka, there have been many days with personnel losses around and even over 1000.
You are right that the past 3-4 weeks have been insane. Which may be what you call a "jump".
I haven't seen those UK numbers, but It's pretty amazing they are so close.
Yes, obviously the Ukraine numbers will err on the side of positivity but the UK numbers are seen as slightly more factual...at least by the UK media given I get my information from the Guardian podcast. They said 300k around the time Ukraine said 308k.
The numbers here never had a sudden jump, but they have been going up quickly as Russia throws wave after wave of men at Adviivka. There are quite a few videos here of Russian waves being decimated one after another.