Green’s Dictionary of Slang

strip(e)y adj.

[? fig. use of SE stripey, i.e. not plain (and simple)]

1. difficult.

1904

G.B. Lanchester Sons O’ Men 6: It’s boun’ ter be stripy. But bring all yer c’n ter th’ flats.

2. (N.Z.) unconvincing, dubious.

2003