Serial device not added correctly

[baltika_no_9]

Your udev looks quite old

chris@bobby:~ $ apt list udev libudev1
Listing... Done
libudev1/oldstable 247.3-7+deb11u2 arm64 [upgradable from: 247.3-7]
libudev1/oldstable 247.3-7+deb11u2 armhf
udev/oldstable 247.3-7+deb11u2 arm64 [upgradable from: 247.3-7]
udev/oldstable 247.3-7+deb11u2 armhf

Edit - I do not think that udev is causing your problem but your system does appear to be out of date. It might be worth considering updating it.