Weird failure and "Smartctl open device: /dev/nvme0 failed: Resource temporarily unavailable"

in WIN11 I have the issue that my screen is frozen but mouse can move. Used my Debian boot stick to check if it is hardware that is failing. Memory seems to be OK but the SSD is giving me some headaches. *smartctl -a /dev/nvme0* returns: === START OF INFORMATION SECTION === Model Number: KINGSTON SNV2S2000G Serial Number: 50026B7381B094D5 Firmware Version: SBK00104 PCI Vendor/Subsystem ID: 0x2646 IEEE OUI Identifier: 0x0026b7 Controller ID: 1 NVMe Version: 1.4 Number of Namespaces: 1 Namespace 1 Size/Capacity: 2,000,398,934,016 [2.00 TB] Namespace 1 Formatted LBA Size: 512 Namespace 1 IEEE EUI-64: 0026b7 381b094d55 Local Time is: Sun Jun 1 14:22:24 2025 UTC Firmware Updates (0x12): 1 Slot, no Reset required Optional Admin Commands (0x0016): Format Frmw_DL Self_Test Optional NVM Commands (0x009f): Comp Wr_Unc DS_Mngmt Wr_Zero Sav/Sel_Feat Verify Log Page Attributes (0x12): Cmd_Eff_Lg Pers_Ev_Lg Maximum Data Transfer Size: 64 Pages Warning Comp. Temp. Threshold: 83 Celsius Critical Comp. Temp. Threshold: 90 Celsius Supported Power States St Op Max Active Idle RL RT WL WT Ent_Lat Ex_Lat 0 + 5.00W - - 0 0 0 0 0 0 1 + 3.50W - - 1 1 1 1 0 200 2 + 2.50W - - 2 2 2 2 0 1000 3 - 1.50W - - 3 3 3 3 5000 5000 4 - 1.50W - - 4 4 4 4 20000 70000 Supported LBA Sizes (NSID 0x1) Id Fmt Data Metadt Rel_Perf 0 + 512 0 0 === START OF SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED SMART/Health Information (NVMe Log 0x02) Critical Warning: 0x00 Temperature: 40 Celsius Available Spare: 100% Available Spare Threshold: 10% Percentage Used: 0% Data Units Read: 7,508,693 [3.84 TB] Data Units Written: 6,431,227 [3.29 TB] Host Read Commands: 76,389,168 Host Write Commands: 100,940,793 Controller Busy Time: 5,706 Power Cycles: 196 Power On Hours: 292 Unsafe Shutdowns: 97 Media and Data Integrity Errors: 0 Error Information Log Entries: 0 Warning Comp. Temperature Time: 0 Critical Comp. Temperature Time: 0 Error Information (NVMe Log 0x01, 16 of 64 entries) No Errors Logged Self-test Log (NVMe Log 0x06) Self-test status: Extended self-test in progress (26% completed) Num Test_Description Status Power_on_Hours Failing_LBA NSID Seg SCT Code 0 Short Completed without error 292 - - - - - 1 Extended Completed without error 292 - - - - - 2 Short Completed without error 292 - - - - - which looks OK. However after *sudo smartctl -t long /dev/nvme0* I receive: Smartctl open device: /dev/nvme0 failed: Resource temporarily unavailable after a while ,... Do you think the SSD is failing or the controller on the board- or nay other idea?? Unfortunately I do not have a spare SSD here to test. Any hints? Thanky for helping me!