JV's Stuck Throttle Cafe'

I've had my 2016 Ford Explorer for about four years now and it's been such a solid family car – plenty of space for the kids and all their stuff, comfortable on long drives, and generally pretty reliable – but over the last month or so I've noticed the transmission starting to do some weird things that have me genuinely worried. It started with a slight hesitation when pulling away from a stop, almost like it was taking a second to figure out which gear it wanted to be in, and then a couple of weeks ago I felt this really harsh clunk when it downshifted going up a hill and honestly my heart just sank because I know transmission problems are never cheap to fix. I've been trying to be gentle with it and avoid any sudden acceleration, but it seems to be getting progressively worse and I know I can't just ignore it and hope it goes away because that's how you end up with a much bigger bill down the line. I've been asking around for recommendations because I really don't want to take it to just any garage that might make things worse, and I've heard that finding a professional Ford repair workshop in Abu Dhabi is key because these transmissions have specific issues that not every mechanic knows how to handle properly. I'm planning to take it in for a diagnostic this week but I'm absolutely dreading what they might find because I've read about torque converter problems and solenoid failures and all sorts of expensive-sounding things that could be the culprit. The car has about 120,000 kilometres on it which is around the mileage where these issues tend to crop up from what I've gathered, so I'm trying to mentally prepare myself for a potentially costly repair. Has anyone else had transmission troubles with their Explorer of this generation, and if so what was the actual problem and how much did it end up costing to put right? I'm really hoping it's something relatively simple like a fluid flush and a software update rather than a full rebuild because I just don't have that kind of money sitting around right now. Any advice or shared experiences would be hugely appreciated because I'm driving around on edge every time I get behind the wheel and it's taking all the enjoyment out of what used to be a great car.