I am using the LTC3649 in circuit with the LT8364 step-up as 24 V to 37 V converter for the LTC3649 supply. The output voltage of the LTC3649 is set by OA output at the ISET pin in range of 0 .. 35V.
I found similar topic at ADI Eng. zone (https://ez.analog.com/power/f/q-a/110970/ltc3649-datasheet-circuit-fails-when-powered-with-load) so I increase value of input capacitors (2x4u7 -> 4x 4u7 + 220u elit.) but the instability is still present and leads to failure of the LTC3649. There are well visible instabilities at the +36V supply rail. See scope screen below..
I tried to check the voltage at ISET pin but I did not notify any change with the ISET cap change from 10n to 100n. But I hope the "noise" from the OA output should not lead to LTC3649 failure.