Serial Input Basics: example 5, question

Something strange appeared in the serial monitor just now:

Message x:

actual message content: 4 0 . 8 2 , 2 4 . 2 5 , 7 . 6 5 , 4 1 , 2 , A .
ASCII message content: 52 48 46 56 50 44 50 52 46 50 53 44 55 46 54 53 44 52 49 44 50 44 65 46 0 0 0 0 0 0 0 0
Parsed message: 40.82 : 24.25 : 7.65 : 41 : 2 : A

Message x+1:
actual message content: 4 6 . 9 6 , 2 0 . < 4 3 . 3 2 , 2 0 . 7 5 , 9 . 5 7 , 4 1 , 1
ASCII message content: 52 54 46 57 54 44 50 48 46 60 52 51 46 51 50 44 50 48 46 55 53 44 57 46 53 55 44 52 49 44 49 0
Parsed Message content: 46.96 : 20.00 : 20.75 : 9 : 41 : 1

Message x+2:
actual message content: 4 0 . 8 1 , 2 4 . 2 5 , 8 . 0 9 , 4 1 , 2 2 , A . 41 1
ASCII message content: 52 48 46 56 49 44 50 52 46 50 53 44 56 46 48 57 44 52 49 44 50 50 44 65 46 0 0 52 49 0 49 0
Parsed message: 40.81 : 24.25 : 8.09 : 41 : 22 : A

In subsequent messages the identifier keeps being correct: both in the full actual message as in the parsed message. BUT in the actual message content the trailing 41 and 1 keep being present.

In message x+1 in the second float there suddenly appears a < within this number.
In the serial monitor the positioning of this 41 and 1 are always exacty identical, meaning they do appear in the same exact position too in the received message?