sync.py keep crashing aroud 60k block

[bitcoinholder]

sync.py keep crashing aroud 60k block:

Block 67031 is valid. Computed Merkle root match the stored Merkle root.
Block 67032 is valid. Computed Merkle root match the stored Merkle root.
Block 67033 is valid. Computed Merkle root match the stored Merkle root.
Block 67034 is valid. Computed Merkle root match the stored Merkle root.
Block 67035 is valid. Computed Merkle root match the stored Merkle root.
Block 67036 is valid. Computed Merkle root match the stored Merkle root.
Block 67037 is valid. Computed Merkle root match the stored Merkle root.
Block 67038 is valid. Computed Merkle root match the stored Merkle root.
Killed

It happens every time after restarting it and every time around 60k block.
My server has enough memory and free disk space

total used free shared buff/cache available
Mem: 1.9Gi 298Mi 1.6Gi 32Ki 105Mi 1.6Gi
Swap: 5.3Gi 57Mi 5.2Gi

Filesystem Size Used Avail Use% Mounted on
udev 959M 0 959M 0% /dev
tmpfs 197M 704K 196M 1% /run
/dev/vda2 52G 13G 37G 26% /
tmpfs 981M 0 981M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/vda1 511M 12M 500M 3% /boot/efi
tmpfs 197M 0 197M 0% /run/user/0