CRT TV Question

[Alex KL-1]

Another CRT TV question...

Perhaps only a curiosity, but anyway:

In my short carreer fixing CRT TV's I noticed some CRT being strange in the sense of adjusting focus and G2: some become interdependent, like having leakage between the 2 electrodes. Just I have a 17" Toshiba with japanese CRT having this behaviour. But luckly, I'm able to adjust for decent focus. Besides that, this CRT is outrageously insanely bright; the pixels are more bright than the ones in my OLED in HDR mode with peak scenes, and even so it don't blooms or loses focus...

This issue, is a gas issue, is a leakage issue, or is difficult to estimate the cause?