The Wikipedia camera templates are a great place to research where a specific model sits in the lineup and timeline for a camera system.
If you look at the Canon EOS digital cameras template:
You'll see a direct line from the 500D to the current 800D/T7i and 850D/T8i.
They are pushing for the cheapest EOS 3000D but if I'm not mistaken that's like 2 classes ...
Based on the information you provide, the suspected cause for this issue is higher than ususal friction in the lens' bayonet mount and in its aperture actuation mechanics. Possible reasons are:
Damage, e.g. bent parts or corrosion
Dirt has accumulated
Whether repair is required or cleaning and lubricating will solve the issue is ...
It means exactly the same as f/. 1: is just an older syntax for denoting a ratio. You might also occasionally see 1/. Since the f-stop is essentially a ratio of focal length to entrance pupil diameter (the apparent size of the aperture when looking into the front of the lens), one of these notations is used to indicate, in this case, that at the 18mm end, ...
Following the login (my understanding) of Canon replacement of 500D should be 800/850D.
xxxxD is lower class of cameras. About 200D - this is different serie (by own), small size, with most of the options of xxxD serie.
The definition of "the best" replacement is very long discussion, also based on personal opinion :)
Have you checked the auto power-off setting on the secondary camera (the T5i)?
When my Rebel T7 turns off after the timeout, it takes a second or two for it to "wake up" when I half-press the shutter (or press any other button). If the camera is in auto-off and I fully depress the shutter without waiting for it to wake up, it does not take a photo....
Honestly, on paper the current lower tier 2000D/Rebel T7 matches or exceeds just about every specification from the more than a decade old 500D/Rebel T1i.
It does have slightly lower burst rate and buffer: The 2000D can shoot at 3.0 fps for 150 JPEGs or 11 raw, while the 500D can go at 3.5 fps for 170 JPEGs or 9 raw.
One difference you might could have used ...
The 430EX III-RT's built-in transceiver cannot link to the YN-622C-TX. The Yongnuo 622 system is a separate radio system that's incompatible with Canon's RT radio system. While both operate on the 2.4 GHz band, the signal protocols are different. It's kind of like how wi-fi, bluetooth, your garage door opener, and baby monitor all use 2.4 GHz, but don't ...
I'd check whether your flash is set to On or Off on the 7D Mk II. If the hotshoe is turned off, then basically the transmitter's not getting any firing signal from the camera.
Maybe also check that you used the correct sync port on the receiver for a camera shutter, and not the one for flash triggering.
That, or the trigger simply isn't designed to be used ...
Since the pop-up flash on your 1300D can not be used as a Master Flash in Canon's E-TTL optical wireless flash system, you can not fire an off camera 430EX or 430EX II using your EOS 1300D without additional hardware.
To use a 430EX or 430EX II off camera with your 1300D, you have several options:
Use an on-camera TTL Master, such as a Canon 580EX II, 90EX, ...
No, the Canon 430EX can not operate as an off camera flash with your EOS 1300D, unless you add some extra equipment.
More advanced cameras like the 600D, 700D, 80D, 90D, etc. can use the built in, pop-up flash to trigger the 430EX, but your 1300D can not.
You will need to buy a master flash like the 580EX II or 600EX.
Not without additional gear.
Canon reserves a flash "master" for the built-in pop-up flash for the ###D/T#i series of digital Rebels (T3i and later) and higher-end camera bodies. The SL/T### and ####D/T# line bodies do not have this capability.
And Canon's EX-designated and EL series flashes can all be "slaves" in the system, do not have ...
If you are photographing live action sports, the shutter speed is likely to be above the flash sync speed and therefore not trigger the hot shoe circuit.
Of course I could be wrong.
But you can eliminate this as the problem by lowering the shutter speed below the sync speed and testing the system.
If that’s not the problem, see if you can trigger a flash ...