Slow 2015 macbook pro after update to Sonoma

I recently got a 2015 Macbook pro Retina whose maximum supported version is Monterey 12.7 if I'm not mistaken. I decided to force an update via OpenCore Patcher to the latest version of Sonoma as I am an app developer and to install XCODE with Swift6 I need that version. The first few days the macbook ran great despite having forced the upgrade. No crashes or slowdowns. Suddenly, yesterday it started to run very very slow, as if it had lag. The windows opened in jumps, the clicks took a long time to be displayed on screen, the finder icons were black... It started this way after installing Git via brew and, in turn, when I got the option to upgrade to Sequoia (I didn't upgrade). I tried the following: - I uninstalled Git in case that was the error but it didn't fix it. - I also noticed that the hard disk was too full for the applications I had on the macbook and I started to delete cache and apps in case it was a memory problem but it didn't fix it. - I thought it could be that the new version (Sequoia) was automatically downloaded without being installed and I deleted the updates folder of the library and executed some commands by console that I found on the internet to remove possible pending updates. It did not work. - I've also check if there was any problem with the ram or any app consuming too much memory but all looks OK. I have gone back to the Monterrey version and it works correctly but I would like to have it updated to Sonoma to be able to continue working with it. I don't know if anyone else has experienced this kind of error or if you know of any method to upgrade your 2015 Macbook pro Retina to Sonoma in a more stable way. Thanks in advance