I was able to reduce my sample SQL down to a very simple example which shows the problem.
CREATE TABLE tab1 (a int,b int);
CREATE INDEX “IXFK_tab1” ON tab1 (a ASC,b ASC);
Apparently Toad doesn’t like the double quotes surrounding IXFX_tab1. If I remove the quotes, the index is reversed as expected. Otherwise it doesn’t work.
According to https://www.sqlite.org/lang_keywords.html double-quoted names are valid identifiers.