The LUA error below breaks the addon completely. It happened immediately after I joined a group, and a reload UI didn't work. All of a sudden sometime in the middle of the Mythic+ dungeon, the timers worked again.

4084x tullaCC\cooldown.lua:126: attempt to index local 'style' (a nil value) tullaCC\cooldown.lua:126: in function UpdateStyle'
tullaCC\cooldown.lua:152: in function <tullaCC\cooldown.lua:149>

Locals:
self = Grid2iconbuffs0105 {
0 =
_tcc_start = 0
_tcc_duration = 0
}
style = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = "attempt to index local 'style' (a nil value)"
Addon =

{
PLAYER_LOGOUT = defined @tullaCC\main.lua:33
CleanupDatabase = defined @tullaCC\config.lua:47
eventHandler = {
}
SetupDatabase = defined @tullaCC\config.lua:33
Config = {
}
ResetDatabase = defined @tullaCC\config.lua:188
PLAYER_LOGIN = defined @tullaCC\main.lua:28
OnEvent = defined @tullaCC\main.lua:21
Timer = {
}
Display = {
}
Cooldown = {
}
GetDatabaseDefaults = defined @tullaCC\config.lua:54
}
`

This should be fixed in 8.2.2 (release)