Yuka flower troubles

[Ivanhoe]

For the last 2 years I have had a big yuka plant in my garden apx 4/5 ft high start flowering and when the flower stalk from the centre gets to around 3ft with around 20 flower heads the heads stop growing stay closed either and die off .
Ihave noticed this year that there are now 3 seperate crowns on the top of the yuka all with flower growth in them but only the most established one has opened and produced a flower stem .
Hope people can understand what I am on about as I do not know the correct terms to use regarding this problem

[burnie]

Can you take some pictures, it might help us

[Ivanhoe]

Here are some pictures that i have just taken you can see the trunk splitting into three on the first one
The second shows one of the 3 closed flower shoots
and the third shows how the plants main flower has not opened fully this is the second year this has happened .

[Jungle Jane]

It could be that the one with the flower is older,the others could be too young this year but ok next year? I don’t know I just googled it says “Yuccas only bloom when they reach a certain age of maturity and they all bloom according to their own schedule”.
https://www.gardeningknowhow.com/orn...esnt-bloom.htm