Hi OriolVives, welcome to the forums.
I’m sorry to hear this issue has occurred in your save multiple times. You may have already seen it, but in case you have not, there is a Known Issues post on this issue with some potential workarounds here - [Known Issue] Rafts/Gyro Vanishing
The team is investigating and working on this issue. I cannot speak to the age of the issue as I have only worked with the Console team and do not know if this has the same root cause as the one experienced by those on PC.
So far the two most common triggers reported by players are saving immediately after returning to an island or exiting to the main menu, checking the cartographer and loading back into a save. I would appreciate any extra information you can provide about your experience of this issue and if they match the triggers other players have reported.
I understand how frustrating and disheartening this issue can be for players and how it can disrupt gameplay but I must request that if you post on the forums that you do so in a respectful manner and adhere to forum rules. I have also edited the title of your post because of this.
As we do not have access to player accounts or saves, I recommend you remove your PSN ID from your post. (If the time for which you can edit the post has elapsed and you wish it to be removed, please let me know).