No Cakewalk by Bandland Forum yet, so here.
 
Audio clip will not extend with any reverb, delay or length adjustments....

I'm not sure what you are trying to do - could you please clarify? Are you maybe trying to slip-stretch a clip?
 
Slip stretching
https://www.cakewalk.com/Documentation?product=SONAR&language=3&help=AudioSnap.19.html
 
Or maybe you have issues with freezing cutting of your effects tails, in which case I might quote Bitflipper's explanation from the post below: "Just drag your last MIDI clip (slip edit) out to the desired length. That will determine where the freeze bounce stops."
 
Freeze tail duration
http://forum.cakewalk.com/Freeze-tail-duration-m3307407.aspx
 

This is not a MIDI clip.
 
And I'm more than sure I made it clear what I am attempting to do.
 
Length.  Reverb.  Delay.  If you need me to explain it to you, when you extend the length of a clip... the clip is supposed to lengthen!!!!!
 
When you Use Reverb, the clip is supposed to... lengthen!!!  As long as the reverb would extend!!!
 
The clip DOES NOT EXTEND.  It cuts off at the length of the clip and does not extend.  There is no possible way for me clear it up any more than that!

Are we SERIOUSLY stuck with only communicating with forum members, with Cakewalk or Bandlab not bothering to read any of our concerns???
 

Why so hostile to someone trying to help you? Sometimes the best help for products come from the people using it in a similar way as you. This IS a user forum. In fact it’s a user forum for a product technically dead, so please save the hostility (if you must) for the actual company. Responding like this is not likely to resolve your problem any faster

TheRedGuy90
Are we SERIOUSLY stuck with only communicating with forum members, with Cakewalk or Bandlab not bothering to read any of our concerns???
 

this is a user forum, contact support directly if you want to hear from them specifically

TheRedGuy90
When you Use Reverb, the clip is supposed to... lengthen!!!  As long as the reverb would extend!!!

No it's not. The clip will be as long as you recorded it to be i.e the length of the recorded program material. If you add a reverb or delay plugin on that track you will hear the reverb or delay tail, but the clip length will stay the same. You can extend the length of a clip by dragging the edge with the mouse.

I tried extending the clip before applying Reverb, but it still cut off at the point the audio had ended previously, and I was baffled.

we are not bandlab, but some of these guys here could easily work for them.  i have gotten more useful help here than from any customer support rep.  might take some patience , but someone here can likely figure it out
 

also, although your description is very self explanatory to you because you know all the subtle details, there are still unknowns to us.  Is this a clip you bounced? was reverb appliued directly to clip? was revereb in fx bin or or pro channel? are your affects pre-or post fader? is your reverb on a send? There are many possibilities we cannot assume.