Transmission Fail Safe Mode

[Clinticus]

New BMW owner, new e53 X5 owner and new poster wondering if this issue has been solved in another post or forum if so please direct me to the proper location. When started cold X5 will shift through all gears and run smoothly at highway speeds. Once warm it will skip 1-3 and “thump” into 4-5 in both manual and auto driving causing trans fail safe. Here’s what I’ve done so far:
Replaced transmission cooler and thermostat, drained and filled trans fluid and replaced filter and gasket according to guidelines, replaced speed output sensor (P0721 code), replaced trans wiring harness (including temp sensor), drained and filled TC fluid, drained and filled engine oil and replaced filter (Valvoline MaxLife used for all fluids), drained and filled coolant according to guidelines (blue European 50/50), replaced power steering pump (was going out) and drained and filled fluid (MaxLife ATF), replaced fan clutch pulley (cracked from previous power steering pump being installed incorrectly), replaced MAF, cleaned ECM, about to replace B2S2 O2 sensor (P0440, P0057), engine average temp 103 C, trans average temp 95 C, battery average 13.4 - 13.6v running 3000 rpm’s. No longer pulling code P0731 now pulling P0733. Btw purchases vehicle 12/2019 with 144k miles and discovered most of these solutions from this forum so EXTREMELY grateful this exists! Hoping someone can assist with potential a solution other than a complete transmission rebuild!