1/2 vs 2/4 online

[Gnome XXL]

Hi. I'm a regular lurker, but rarely post so far.

I started playing hold 'em about a year ago, and LHE in the last six months or so. I am very interested in improving my game, and to that end, I have studied more than a dozen books, and have a membership at a training site.

I play 1/2 - 3/6 (full ring) online and 10/20 live.

I have a very solid win rate at 1/2 over almost 30,000 hands and feel confident playing at that level. However, after about 8,000 hands at 2/4, I appear to be losing steadily.

I 8-table, and currently play half the tables at each level. My bankroll is more than adequate for this purpose. (I work full-time... this is a hobby). My PT stats are ~16/8/2.2.

I understand that my results could be a result of variance. My question is: are there any adjustments that I need to make to my game specifically to be successful at 2/4?

Anyone's experience or comments are welcome. I will provide any further information requested.

Thank you for your time.