Unitframe health text changing randomly from % to healthvalue

[jonomurphy]

For some odd reason, whenever I get invited to a group by people, I often see their health as the actual value - followed by the % symbol; it is set, however, to show health: percent. When this happens, if I target one of the group members, the health on the target frame also changes to the actual value - but this doesn't apply to NPCs (which shows the real %).

It works when i invite people to my groups.

https://media.discordapp.net/attachments/603481488381706240/743793868407046264/WoWScrnShot_081420_123046.jpg?width=1204&height=677

https://media.discordapp.net/attachments/603481488381706240/743793648214343700/WoWScrnShot_081420_122949.jpg?width=1204&height=677

https://media.discordapp.net/attachments/700681162225352754/743868442053967932/WoWScrnShot_081420_172209.jpg?width=1204&height=677