Reaper 6: SL plugin edits not saved into the session even on tracks or item FX

Hello everybody.

I’m testing before buying SL 6.0.20 Build 195 with Reaper 6.02 64 rev 992e2b (Dec 16 2019)
After applying some changes i a instance SL 6 plugin even on tracks FX or Item FX when I re-open the Reaper session I lost the precedent changes 'casue I got the SL plugin restarted from scratch and I lost the already changes that I applied before closing the session. On Studio one… demo SL 6 plugin status is saved into the session. Unfortunately I have Cubase 8.5.
Any suggestion?