Unacceptable behavior in recording speeds, large fluctuations especially when full, I will never buy it again.

I bought it for around 86.00 EUR. Amazing price for a 2TB SSD. I need it for frequent copying of large files, ranging from 800GB to 1.3TB.
However, during the copying of large files, after around 100GB of copying (around 10 minutes), the speed drops from 430MB/s to 10MB/s!!!! and stays there forever until the file is copied, meaning it becomes slower than a USB 2.0 stick. I have tried countless tests and combinations of computer hardware without any changes. I searched for it on the internet and it seems that this phenomenon often occurs with this SSD model.
If you want to copy small files at high speed and have a large storage space, you will be satisfied. If you need it for copying large files, it is the worst choice.
NEW OBSERVATION: - CAUTION - This behavior of the disk is considered normal by the factory and is not a warranty issue. They do not accept it as a warranty because they consider its usage as not normal, meaning it should not be used for copying large files!!

I bought it for backup use in order to get rid of the delays of the old 2TB HD I had for this job.
Currently, it is 70% full and "CrystalDiskMark" v8.0.4 confirms Read Speed and Write Speed close to 550 MB/s and 500 MB/s respectively.
The issue, of course, is the lifespan which we will see over time. I found it for €85 and currently it has one of the best prices for this capacity.
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Later ADDITION
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After 2 months of use, and while it has 450GB free (we're talking about the 2TB one), it creates periodically (without knowing why and without being able to find a solution) the following issue: the disk becomes painfully slow, literally like a flash drive, and then the benchmarks show that the write speed has dropped from 450MB/s to just 15MB/s... The strange thing is that the benchmarks show that the read speed is not affected. This speed drop lasts for a long time.
In the last 5 years, I have used and changed at least 10 SSD drives from different companies, but this is the first time I see something like this. Solutions like simple restart, system restore, uninstalling the drive from the device manager did not work. "Hard Disk Sentinel" shows that the disk is perfectly healthy and in all reports it does not show the slightest problem. It also shows that 25% of the disk is free, so there is no delay due to excessive fullness.
This problem did not occur during the first few days, but because it frequently loses its speed lately and becomes annoying and problematic, I lower the rating to 2 stars. The speed recovers on its own for unknown reasons, but it lasts for a few GB of copying and then the same thing happens again. I have read about delays that occur when the cells of the flash memory in the SSD are filled. Anyway, it is a serious problem when you need to wait a multiple amount of time to copy a few GB of data.

[after 8 months of use and 360GB free, the problem persists.
speed example:
40GB copy from an NVMe to a Patriot 210 512GB SSD = 10'43'' (150GB free)
40GB copy from an NVMe to a Kingston 480GB SSD = 8'04'' (100GB free)
40GB copy from an NVMe to the mentioned Patriot 220 2TB SSD = 44'16'' ]

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Overall, after only 15 months of life, it has now stopped working and the PC does not recognize it anymore

It was purchased to revive my old computer that was bought back in 2009 with an Amd Phenom II 3200Ghz, 8Gb Ram DDR3, and VGA R9 270X! I now use it for simple internet use, retro gaming, and generally any games it can handle, as well as for movies. It only takes a few seconds to load Windows 10 pro with all the latest updates!

It was purchased to revive a very old 2009 Acer laptop with 8GB DDR3 RAM and Bluray, which was running slow! I only use it during vacations to watch movies, for internet use, retro gaming, and temporary photo storage during vacation periods. It only takes a few seconds to load Windows 10 Pro with all the latest updates.