Automatic transmission

[TomIre]

Having an issue. Twice in the last couple of weeks the auto transmission has sort of hung up in neutral for a few seconds before shifting as normal. Yesterday, coming in to a roundabout I guess as it was downshifting it went into neutral and wouldn't shift out. I coasted to a stop and tried the paddle shifters both in auto and manual. No luck. Wouldn't go into reverse either. Turned it off and back on and second time it shifted as normal and I completed my journey. 
Ant thoughts?  
I'd like to check the transmission fluid but I believe I need to remove a wheel - correct?
Any and all advice appreciated!

[Sol]

It's not transmission fluid like a conventional automatic, it's a regular manual gearbox with an electronic (robot) clutch and gear shift.

The gearbox contains normal gear oil, you would know if it fell out, it's thick and stinks. There is no dipstick for this.

Most likely your gearbox ECU took a fritz, what year of vehicle do you have? Handy to know. Always put it in the thread or in your signature. Saves us guessing!

The ECU for the gearbox can only be scanned for fault codes using Citroen Diagbox, or a high end professional garage scanner like Autel Maxi 808 or Snap-On. Cheap OBD tools will not work for this. I'd get it looked at, if it happens again it may not reset and you will be stranded.

[TomIre]

It's a 2015. Local Citroen dealers can't see me until the end of the month. I've got plans for a local garage to take a look Tuesday. Big garage but not sure what reader they have. Ran OK yesterday, but . . .

[Sol]

Yes exactly, you never know. To be honest after being in machinery automation myself for many decades, the first few hiccups are often signs that something is about to fail.