UNC with 14 character computer name

User maps network drive in Windows Explorer to \\[14
character computer name]\data on network with TCP/IP
only. User is able to ping [14 character computer name]
from command prompt without issue properly resolving to
correct IP address. Initial mapping appears to work but
Windows Explorer shows "data on [10 character computer
name] F:" rather than "data on [14 character computer
name] F:". The computer name is truncated to 10
characters. The original computer name is 14 alpha
characters with no special characters, spaces, or
numbers. Subsequent boots of workstation say that the
permanent connection is not available and any use of the
F drive fails because the [10 character computer name]
does not exist. This system was working fine last
Friday. What could cause this condition?
Thanks for any help.