Though both lines equal out to 0, as they are both on the Bank Statement Lines panel, they cannot be directly matched to one another.

However it is possible to do so by selecting the two lines while matching another transaction. This way as the net difference from that transaction will be 0, so the system will allow you to carry on.

In below sample, we are actually matching Bank Statement 3rd line (Amount 341.25) to BC statement 1st line (341.25). But while doing this, we can select those reversal transaction lines from Bank Statement as well. system will allow to proceed.