Ice out questions from a float tube

Hi I bought my first float tube last year (Creek company odc420 ul ) and absolutely love fishing from it in trout ponds, I did exceptionally well last summer and fall when hatches were abundant and fish we're feeding, many salmon and brown trout. But this ice out sub-surface fishing for brookies and salmon is skunking me pretty hard and I can't figure it out ( always been a stream Fisher ). I've been out numerous times fishing wooly buggers of all sorts and clouser minnows, and Mickey Finn's to the shorline and deep drop offs with a fast sink tip line, stripping, drifting, letting sit, everything. Ive even tried midges under an indicator the other day when there was casings all over the lake. But no such luck besides seeing 1 trout surface. I'm still having a blast and going to keep trying this weekend for some hopeful success, but the forums here won't let me search and I'm just looking to see if anyone has any advice or tips that they can share with me. I'd greatly appreciate it! Thank you.