Direct the water spray at the base of the shower door bottom track. Focus on not spraying into the track, rather at the side of the track and where the track rests on the enclosure
Have an assistant monitor the floor outside the shower with a towel in hand, just in case
If no water is detected outside the shower, now concentrate the stream straight down onto the track but not at full-force. The goal is not to fast-fill and over-top the the track. The goal now is to see if water is leaking from the track and out
no water on the floor after the test. We also use a shower curtain and made sur that the curtain was against the wall. Could it be coming from the toilet? Occasionally we hear a drip, drip, drip, after a flush but cannot determine where it is coming from or where it is going..
I have battled a water leak from the Shower on and off for 7 months. Replaced the drain, repositioned the shower drain , etc. Ran an inspection scope up the walls looking for a source of the leak, it can dump a lot of water sometimes and run under the bed to the closet. I noticed that there is no sealant between the shower insert and wall panels. I used a 100% silicone based sealant and it has stopped the leaking ...for now.
I had a horrible leak from day one in my shower come to find out the shower door drip rail which is the bottom door tracks was installed backwards so all the water the runs down the glass while taking a shower spilled out into the bathroom instead of back into the shower pan. I like you noticed there was no sealant around the shower door frame
We had the same issue in our current 2017 Jayco TT. The shower door track was not sealed enough in the corners where it meets the wall piece. I gob of clear silicone sealant took care of most of it. We do occasionally get a drip but I just wipe it with my towel so it doesn't get into the wood.
If you suspect the toilet, pay close attention to the piping on the back side. Could be a loose fitting or a fitting that was over tightened and has a slight crack. What model camper is it? Might be a specific issue that another owner has come across.
I noticed same issue on our last trip in our 310RL with water around base of toilet. Put some Teflon on a fitting in back of toilet where it seemed to be dripping from. Helped, but the issue came back after flushing the toilet a few times. Noticed something odd, however. Normal flushing = no water. Multiple flushings at a time to ensure plenty water in black tank and the water leak/puddling reappeared. Crazy. Not sure why that would happen but it is. Rig has been sitting a few weeks now - going boondocking this coming weekend then WDW Fort Wilderness NEXT weekend. Will see if the issue reappears.