i have a variegated cheese plant since 1996... at the start it had split leaves unfurling... it was a small cutting when i got it... and i was thinking the same as someone here pointed out... that they were still splitting because they were part of an original mature plant... for a long time this plant did nothing... it merely survived... and barely a new leaf in 6 years or more... then this year i decided i needed to do something... so i repotted into good loamy compost... and bigger pot... bought larger moss pole and unravalled the plant... and tied it up to the new pole... then i bought some good biological plant food... with dropper which was a liquid feed when added to water(i prefer rainwater) that will cancel out problems with toxic water...the plant has now doubled in size over the summer and variegation is stronger... leaves are coming out fast...yet... not split :( i feel like its more of a simple philodendron and or the age of the plant this is very disappointing... any advice? i do keep it in bright light though not sun..

How about heliopsis Prairie Sunset or Rudbeckia subtomentosa (sweet coneflower)'Henry Eilers'?

That's what I did with mine...tied it to a pole.....actually it was a birch log/sapling that the County had cut down. Just be sure you have it in a heavy clay pot before inserting the pole, as the pole/plant combined create a lot of extra weight. I've had to put mine against the wall due to the weight.

Probably bacterial or fungal, associated with the plant having been kept wet before you got it