UPDATE: SOLVED
Tried multiple things but only one solved the issue, accesing Microsoft Configuration (Win+R and writing mscongif), inside the services section, I marked the "Hide all Microsoft services" and then tried disabling all services left and re-enable them one by one and testing. The one apparently responsible for the issue was "Elevoc Control Service".
I hope this is useful for some people!.
Note: Updating drivers, trying to optimize in NVIDIA App, setting an fps limit, disabling v-sync, setting Apex Legends on high performance mode in windows settings, etc. etc. etc. DID NOT work.