Things to keep in mind:
The H90 does not store loops – if you switch to a different program (or away from the looper preset), the loop is gone. You can do all sorts of amazing things to the loop, and the looper algorithm (/preset) is really robust and an amazing tool for creative live manipulation. But unlike many other loopers (such as the EHX 720), the loop cannot be saved or exported.
The H90 pairs two presets together in each “program,” and changing one of the presets usually means switching to a new program in normal usage. (Example: program X has a chorus and a reverb, and if you want to change that chorus to a delay (for example) you need to make a second program with a delay and reverb, rather than just switching the chorus to delay). When using a looper, changing the program with erase the loop when the H90 loads the new program.
Work around: You may be able to (manually) switch the “other” preset after recording the loop to something else by manually scrolling through the different presets for the non-looper preset slot. (I have not confirmed this). There are some “filters” for navigating through the (vast) lists of presets, but it would still need to be done by hand.