Any recommendations for a wireless camera? I like to keep a couple handy for users that want to temporarily record a specific area. Thanks.

The Reolink RLC-511W is good, has power Zoom as well...

Ive been running 4 Yucheng wireless for over 2 years now 24/7. Cant beat the price for a 5mp, 20x "optical" zoom wireless , 200 bucks off ebay. Full 360 PTZ also with humanoid tracking. I did have one slight focus problem with one when I received it. The place is in HongKong (4 day shipping via dhl from ebay) and they team viewered in for 30 minutes to check it for me and see if they could fix it. After they said it had a problem, they shipped me a new one within 4 days, and I didn't have to return even the old one. I was impressed, that's customer service. Yeah some might say they are cheap china cams, but I'm 120% satisfied with mine after the 2 years use and all 4 still working fine. BTW I get a 200 foot wifi range on the one farthest from my house (mounted on my polebarn in back) with a 9db antenna I swapped out on it. IR night range is a good 300 feet that I can see in total darkness also. Blue Iris doesn't have a Yucheng built in profile for the 5mp camera model, but using Generic/ONVIF everything work fine. The *only* drawback I see is the min. 12 foot focus distance . You cant use it in some tight quarters like say a hallway as a cam to get close up stuff, even at the min. zoom setting.
https://www.ebay.com/itm/20X-ZOOM-Wirel ... Stk_4Ax-DA

Can I ask what PTZ settings you are using for you yucheng cameras? I can't see to get them working. Thanks for your help.

I've had pretty good luck with the Foscam R2 series and the Amcrest 841 series. I have two R2 cams that are used over wifi- as long as they're in a decent location they're very stable (they're only ~30 or 40 ft from the router, so it's not what I'd call a fair test).

Be aware that wifi is generally considered an unreliable solution in the long run.