Agree with the above responses ++++
Here is what I would do:
Make a list of what has changed. Things like the fish/bioload, lighting (even consider ambient light not just overhead artificial lighting), quantity/quality/frequency of nutrients, your water source etc.
Look for any changes, even seemingly inconsequential things like window shades or curtains being pulled to keep the room cooler. Massive water changes can affect the plant. Doing repeated water changes to stimulate spawning and at the same time, cleaning the filters can affect this plant if nutrients are not replaced. In summary, make a list and document the changes to prevent whipsawing.