Razer DeathStalker V2 Pro began to have problems when saving profiles to internal memory. The Razer Naga V2 Pro had a similar problem (discussion link below), the problem took a long time to resolve, but was eventually resolved. You have experience, we kindly ask you to solve the problem for the Razer DeathStalker V2 in the next updates Razer Synapse for the Razer DeathStalker V2 Pro.
Updating drivers, resetting drivers, rebooting and changing the operating system do not help, the problem is of a software nature.
Thank you in advance !
The Razer Naga V2 Pro had a similar problem (link):
https://insider.razer.com/razer-support-45/razer-naga-v2-pro-profile-issues-44493/index3.html