random SSD turn off - ext4_find_entry , reading directory lblock0

From last 2 weeks I have problem with my SSD in GNU/Linux. I think it's not device problem but I'm not sure. From time to time (every 1-2 days last days) I loss physical access to the disk, as if it was disconnected or powered off.

The error:

EXT4-fs error (device: sda2): ext4_find_entry:1465: inode #1308161: comm NetworkManager: reading directory lblock 0

I've typed this error from photo so it can be not fully accurate.

Notes:

Device is always the same "sda2", haven't noticed error with other (big home) partition. I will try to check this next time. Inode and process name changes but NetworkManager is quite common. lblock is always 0.

Hardware:

Dell E7270 with SSD disk LITEON CV3-8D512-11 SATA 512GB

Software:

Debian testing, kernel 4.11.

smartctl brief output:

Device Model:     LITEON CV3-8D512-11 SATA 512GB
Serial Number:    TW0956WWLOH006CU022Z
LU WWN Device Id: 5 002303 100ce15e0                                                                                                                                         
Firmware Version: T89110D                                                                                                                                                    
User Capacity:    512,110,190,592 bytes [512 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    Solid State Device
Form Factor:      M.2
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ATA8-ACS, ATA/ATAPI-7 T13/1532D revision 4a
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Wed Jul  5 12:32:39 2017 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

...

SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  5 Reallocated_Sector_Ct   0x0003   100   100   000    Pre-fail  Always       -       0
  9 Power_On_Hours          0x0002   100   100   000    Old_age   Always       -       327
 12 Power_Cycle_Count       0x0003   100   100   000    Pre-fail  Always       -       335
175 Program_Fail_Count_Chip 0x0003   100   100   000    Pre-fail  Always       -       0
176 Erase_Fail_Count_Chip   0x0003   100   100   000    Pre-fail  Always       -       0
177 Wear_Leveling_Count     0x0003   100   100   000    Pre-fail  Always       -       59
178 Used_Rsvd_Blk_Cnt_Chip  0x0003   100   100   000    Pre-fail  Always       -       0
179 Used_Rsvd_Blk_Cnt_Tot   0x0003   100   100   000    Pre-fail  Always       -       0
180 Unused_Rsvd_Blk_Cnt_Tot 0x0033   100   100   005    Pre-fail  Always       -       2688
181 Program_Fail_Cnt_Total  0x0003   100   100   000    Pre-fail  Always       -       0
182 Erase_Fail_Count_Total  0x0003   100   100   000    Pre-fail  Always       -       0
187 Reported_Uncorrect      0x0003   100   100   000    Pre-fail  Always       -       0
194 Temperature_Celsius     0x0003   100   100   000    Pre-fail  Always       -       76
195 Hardware_ECC_Recovered  0x0003   100   100   000    Pre-fail  Always       -       0
199 UDMA_CRC_Error_Count    0x0003   100   100   000    Pre-fail  Always       -       0
238 Unknown_Attribute       0x0003   097   100   000    Pre-fail  Always       -       3
241 Total_LBAs_Written      0x0003   100   100   000    Pre-fail  Always       -       4293005286
242 Total_LBAs_Read         0x0003   100   100   000    Pre-fail  Always       -       3510503294

SMART Error Log Version: 0
No Errors Logged

SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Extended offline    Completed without error       00%       298         -
# 2  Short offline       Completed without error       00%       294         -
# 3  Offline             Interrupted (host reset)      80%       294         -
# 4  Offline             Interrupted (host reset)      10%       294         -
# 5  Short offline       Completed without error       00%       294         -
# 6  Short offline       Completed without error       00%         1         -
# 7  Short offline       Aborted by host               90%         1         -

Ideas:

• run bad block check
• check connections