PHY 0:01 not found instead of PHY 0:1c not found

Hello

i declare in devices.c 2 VLAn adresses 0x1c and 0x10, sometimes when i boot kernel it's OK i get

[    5.579437] PHY: 0:1c - Link is Up - 100/Half                                
[    5.599822] PHY: 0:10 - Link is Up - 100/Full                                
but sometimes i gat :

[    1.763885] PHY 0:01 not found                                               
[    1.774017] PHY 0:00 not found   

why is kernel using these adresses sometimes ?

thanks

regards