Yes, the two piece Hollister "click" tends to separate bag from wafer and leak.
I thought my leaks was from underneath where wafer meets skin for the longest time because spew would reach the skin and burn hiding the real source of the problem.
I started super glueing the two piece into a one piece and the problem disappeared to use up the remaining supply and then switched to a one piece Coloplast Sensura Mio convex and my life got a whole lot better. Their Velcro tabs extend to the left and right and out of the way of spew, no need for a clamp.
I hear their two piece actually has a clamp or locking mechanism but never tried it out since the one piece is a heck of a lot cheaper and I learned to wash the bag using antibacterial dish soap while on the toilet and change both bag and wafer every 4-7 days at the same time. So a two piece didn't make much sense to me with a Ileostomy but perhaps with a colonoscopy it's different situation.
You can horizontally weaken the one piece wafer so it's not stiff when you bend over some like when getting up etc but I would avoid bending over completely, a lot depends how strong your wafer is adhered to your skin to bend the wafer, why I use paste and mix a little stoma powder to get it to hyperactivate to set harder and faster.
I think the Hollister ecosystem are made cheaper to be used more in volume and disposable like what occurs in many hospitals as nurses tend to change the wafer more often (due to having to look or scabs from healing) and don't (or can't) wash/replace the bag as the patient is bed ridden and winds up leaking regardless. But once outside a much more durable and patient comfortable bag and wafer is better and in my experience Coloplast is the best of the major three for long term comfort.
And I'm sorry to say (gross content warning!) that dogs sometimes eat their own fecees and racoons would tear through my garbage to get to my used bags to eat them. So perhaps yours is wondering why you haven't eaten that food laying on your chest. 😆
I would, after taking off your used wafer, to rinse it outside or into the toilet some and have a look at the areas and around your cleaned off stoma to discover areas where leaks are occurring.
Sorry if I appeared gross and caused anyone to lose their lunch. 😢