It’s already been a known issue for a rather long time that top winstreaks aren’t saved or depicted on the player profile(or at least not on every one). A previous thread already mentioned the issue but it didn’t seem to be concluded what may be the reason or if it will be patched. I brought some screenshots for you to see that it doesn’t work, at least not on Steam, Windows 10
All matches happened in silver division, on some the opponent conceded before lethal.
It’s not nice to see the possibility of your winstreak being displayed but then it shows only 0 even though you know you have got some already.
There may be a forum or blog post where the issue has already been adressed by the developer, but I wasn’t able to find it.
Takio(Windows 10, Steam)