Phase locking two E8257D's for pulsing two different frequencies?

[Plasmateur]

Hello, I am having an issue with pulsing two different frequencies with the goal of each pulse starting at 0 phase even with the 10 MHz clocks linked

I have two aglient/keysight E8257D signal generators. Each one is set to their own respective frequency.

f1 = 4.5 GHz
f2 = 4.057 GHz
difference = 7 MHz

I have each one in pulse mode and they are set to an external trigger. When I trigger them, they do not each start at 0 phase. The one that is off of some multipul of the 10 MHz clock (f2) just jitters about.

I have no problem setting this up so long as each frequency is a multiple of 10 MHz.

f1 = 4.510 GHz
f2 = 4.520 GHz
Difference = 10 MHz

The above scenario works perfect every time. Why is this? Is there a way to pulse these signal generators so they are locked to begin at 0 phase each when not at a multipul of 10 MHz?

The only way I can think to get around this is to use my Siglent SDG6052X and 2 frequency multipliers. What do people do when they need a setup like this?