No pics.

Make sure they aren't too big. Use the Photo button and wait till the image shows full colour before you try and send.

Fof

Can't help, but they do look like something has made a nest in the hole.

To help the gurus here (not including me) give them a location.

Fof

Have they been getting too much water ?

what is the drainage like in this spot ?

ron

The general bareness in the last shot is likely to be due to shading, both from their own foliage above and from the solid fence. To which they are planted much too closely to be allowed to grow for some years without having been kept as a small, sheared hedge. (Both too close to each other and too close to the fence).

"leighton greens" seems to be a name used in Australia. None of the nurseries that hawk this junk in the Mid-Atlantic would even know what 'Leighton' refers to. (one of the cultivar names vs. the name of the overall grex, leyland cypress) I saw mercifully few of them when I was there, or in NZ. The availability of vastly superior hedging material (a huge selection just in the genus Pittosporum) seems to have prevented them becoming very popular. On old farms in rural Victoria, Monterey Cypress were somewhat common.

www.elmsavers.com.au/factsheet/pests-and-diseases/cypress-canker

Leighton Hall in Wales is where C. Leyland was raising Leyland cypresses starting in 1888. J. Naylor raised what became 'Leighton Green' on the same property in 1911, with the cultivar having come to this continent by 1950. However at the present time even the RHS Plant Finder is showing only a single supplier of material grown under the name:

https://www.rhs.org.uk/Plants/Nurseries-Search-Result?query=283735&name=&view=listView&cbMailOrder=f%2Fplant_finder_nurseries_mail_order%2Fy&context=b%253D0%2526hf%253D20%2526l%253Den%2526q%253D283735%2526sl%253Dnurseries