Odd problem with call time limits (Dial 'L' option)

I’m wondering if there have been any reported regression problems with Asterisk 10.1.2 regarding call time limits (Dial ‘L’ option)?

I am experiencing buggy operation with different symptoms on different servers (both running 10.1.2). On one machine the command:

exten => 461,1,Dial(SIP/461,45,L(220000:180000:60000))

results in the initial notice being played properly and the call terminating at the proper time, but ‘repeat’ warnings are played intermittently, sometimes one or two warnings will be played at the requested 60-second intervals and at other times no warnings will be played.

On a second machine the same command will result in an initial warning of ‘you have two minutes and 59 seconds’ (instead of the correct ‘3 minutes’, as occurs on the server above), and then the call will terminate approx. 20-30 seconds later (with nothing unusual in the log.) Again, just very odd and buggy behavior, with different symptoms on different servers.

In both cases the CLI debug log shows:

– Executing [461@LocalSets:1] Dial(“SIP/360-0000000e”, “SIP/461,45,L(220000:180000:60000)”) in new stack
> Limit Data for this call:
> timelimit = 220000 ms (220.000 s)
> play_warning = 180000 ms (180.000 s)
> play_to_caller = yes
> play_to_callee = no
> warning_freq = 60000 ms (60.000 s)
> start_sound =
> warning_sound = timeleft
> end_sound =

so it would appear that all is normal. Given that no errors seem to be showing in any logs I’m not sure where to go with this and any suggestions would be appreciated.