Is there an option to modulate LFO's rate without the LFO re-syncing to song's starting point?

So I’ve got an LFO1 modulating a parameter, and another LFO2 modulating LFO1’s rate. LFO1 mode is set to sync. However every time LFO2 (sine) modulates LFO1 (saw), LFO1’s position switches, thus creating a random effect on the parameter. It’s jumping all over the place and I want it to run freely (it’s tied to Shepard Tone knob). I’ve tried other modes and none works for my goal. Is there an option I’m missing? inb4 RTFM

Hi. To anyone who’s reading this. Eventually I’ve mapped the parameter to a macro and used Ableton’s LFO. Cheers.