ZyXEL 326, USB drive and hard disc switch device names between boots. Is that normal? (1 reply)

I did find something strange: The device names for hard drives and USB-drives can switch between boots.

This is both from the same device.

Just after I have updated from 6.6.2 to 6.7.5, before reboot USB is:
sdb1:

root@debian:/boot# lsblk
NAME      MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda         8:0    1  10.9T  0 disk
├─sda1      8:1    1 139.7G  0 part /
└─sda2      8:2    1  10.8T  0 part /media/data
sdb         8:16   1 114.6G  0 disk
└─sdb1      8:17   1 114.6G  0 part
sdc         8:32   1  10.9T  0 disk
└─sdc1      8:33   1  10.9T  0 part /media/data2
mtdblock0  31:0    0     2M  0 disk
mtdblock1  31:1    0     2M  0 disk
mtdblock2  31:2    0     2M  0 disk
mtdblock3  31:3    0    15M  0 disk
mtdblock4  31:4    0   110M  0 disk
mtdblock5  31:5    0    15M  0 disk
mtdblock6  31:6    0   110M  0 disk

After reboot USB is:
sdc1::

root@debian:/boot# lsblk
NAME      MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda         8:0    1  10.9T  0 disk
├─sda1      8:1    1 139.7G  0 part /
└─sda2      8:2    1  10.8T  0 part /media/data
sdb         8:16   1  10.9T  0 disk
└─sdb1      8:17   1  10.9T  0 part /media/data2
sdc         8:32   1 114.6G  0 disk
└─sdc1      8:33   1 114.6G  0 part
mtdblock0  31:0    0     2M  0 disk
mtdblock1  31:1    0     2M  0 disk
mtdblock2  31:2    0     2M  0 disk
mtdblock3  31:3    0    15M  0 disk
mtdblock4  31:4    0   110M  0 disk
mtdblock5  31:5    0    15M  0 disk
mtdblock6  31:6    0   110M  0 disk

Is that normal or should I be worried?