I’m sorry but you are being one-eyed in this regard. Plenty of teams blow matches they should win. That would be true of perhaps half of all close matches - one side is ahead and they either go on with it (about 50% of the time) or get run down.
Think about it logically - Tigers are the only team who blows games they should win? No of course not. Then logically it extends that a number of other sides blow leads. So perhaps you are saying that the Tigers are the only team that has a “habit” of blowing leads?
Well that then assumes that most other sides who get in front in a match, stay in front. Because if they didn’t, if they got to the front but were run down, with any regularity, then they would also be sides that had a habit of blowing leads.
I truly look forward to all these future NRL games where teams are 6 points ahead with 30 mins to go (as per last night) and 90% of them win.
In fact can you even state the last time Tigers blew what could be considered a winning lead? Rd 8 last year we were up against Parra but they scored with 12 to go; that was a see-saw game, would not have called it a game we blew.
So the answer then, in my opinion, is Rd 7 2018 where the SKD scored that late try for the Knights. The Roosters game Rd 13 we came home late rather than giving up a lead. The Broncos game Rd 3 was another see-sawing game - we only led by 2 and they got a borderline penalty, then we kicked the FG to draw level.
Thus we are looking at 2 games lost where we probably should have won - Rd 4 2019 and Rd 7 2018. That’s some habit we have.