Several years ago I upgraded the lights over the dining table from incandescent to LED, with a dimmer. This has worked well; no flickering visible at any level.
Recently I replaced 2 of 5 under cabinets from T12 flourescent to T8 flourescent. I installed new, likely electronic, balasts with the new T8s.
The undercabinets work fine whether the LEDs are on or off.
The LEDs work fine when the undercabinets are off. However, when the flourescent undercabinet lights are on, the dimmed LED over the table flickers at all but 100% power.
I do not know if there is a shared neutral between the two circuits. They are on different breakers. Home was built 15 years ago.
Would upgrading to a newer dimmer solve the problem?