I too struggle with this.
The problem that I have with the style of Ecumenism employed by many today is that when you refrain from pointing out the areas of separation between The Catholic Church and the numerous Protestant sects, you are giving an implicit stamp of approval to their beliefs. The razors edge that you walk becomes troublesome when you do arrive at discussing the issues which separate us, i.e. the reformation and denial of Church truths. I do not believe the “I’m OK, You’re OK” approach is in the best interest to those who have been fooled into thinking their version of Protestantism is “just as good or better” than The One True Church.
Prior to Vatican Council II this topic was addressed by numerous Popes, and they were mostly of the opinion of remaining at arms length from the Protestants. I understand that times have changed, but to what end do we,as Catholics, do charity to the separated brethren if we do not point out what they have lost by not belonging to The One True Church?
Maybe we need to take a page from the Baptist playbook and spend more time Evangelizing them, with the True, Unblemished, Apostolic Faith in all it’s Glory rather than just getting together for social efforts.