"Insufficient suitable allocatable extents for logical volume" when executing lvextend on striped volume

Issue

• Attempting to extend a striped logical volume (LV) using lvextend fails with "Insufficient suitable allocatable extents":

# lvextend -L+80G /dev/myvg/mylv
  Using stripesize of last segment 64.00 KB  
  Extending logical volume mylv to 311.02 GB  
  Insufficient suitable allocatable extents for logical volume mylv: 20445 more required

[root@host1]# lvextend -r -L+170G /dev/mapper/vgtest-lvtest
  Using stripesize of last segment 64.00 KiB
  Rounding size (181712 extents) up to stripe boundary size for segment (181716 extents).
  Insufficient suitable allocatable extents for logical volume lvtest: 43524 more required

• Using vgdisplay I can see a lot of free space. But when I try to extend a striped LV I receive an error message saying that I do not have enough space.
• Unable to extend LV even though enough free space is available in the VG.