Flowering Quince 'Pink Storm’ - Chaenomeles speciosa

Three planted in 2017, zone 6, as 12-18" shrubs.

Starting in 2018, each has had branches that fully died, from the tip to the join on the main stem. All leaves shrivel and turn brown. Any idea?

One has grown quite a bit and has only a bit of the problem. The other two are more affected and seem to struggle. All three flower, all three suffer minimal deer nibbling in the spring.

Thanks,

Charles