Chandler and Freddie had absolutely no chemistry.
I wouldn't say "no chemistry". The actors were fine in acting scenes. There's quite a few videos on YouTube from WilSon fans that show the evolution of the relationship with Freddie and Chandler in the roles.
Some of the problem is the writing; Sonny seems to have been written to be like a "sunny" golden retriever which meant he would never be the typical smoldering male lead that makes a supercouple on daytime. A decade ago, the WilSon love scenes were ground-breaking for daytime but Freddie always looked restrained. As Freddie got heavier and hairier, he looked even more uncomfortable in bedroom scenes with Chandler.
When compared to Billy Flynn and Greg Vaughn, who were grinding away in underwear in sex scenes, Freddie looked like he was holding back, either because of his discomfort or because of the general paranoia of a gay couple offending the daytime fan base.
Zach Tinker had total chemistry with him. However, I don’t think Chandler is a great actor to begin with. People like Greg Rikaart, Christopher Sean, Colton Little, and Peter Porte have real charisma playing gay characters, as does Zach.
Rikaart, Little and Porte are gay. Christopher Sean is straight but doesn't seem to be as uptight with same sex love scenes when compared to Freddie.
Although Zach hasn't made public statements, I suspect that he's no stranger to same sex relationships, but he definitely was more believable (and comfortable) making out with Chandler in both Beyond and DOOL. The sex scenes definitely changed once Zach was recast into the role. They're not quite to Robert Scott Wilson level but the amount of normalcy in the WilSon bedroom (and shower) scenes was a major leap forward for gay relationships in daytime.
After months of Freddie's ubiquitous black tank top, it was a breath of fresh air to see two men in bed together shirtless when Zach took on the role. That had not happened since Sean Christopher was written off DOOL.
Chandler reportedly got fired for comments he made on the red carpet about whether or not he was re-signing. Killing Will off was such a boneheaded move. Thank god Ron Carlivati corrected that and brought Eileen Davidson back as a bonus to resurrect him. Thank god that passive aggressive bitch, Dena Higley, was shown the door. She openly hated the show and did everything to destroy it and kill off anything gay in it.
It's always difficult to understand the rationale of casting at Days. On one hand, getting a role on DOOL for an adult actor seems to open the door to a lifetime of work, even to the point of bringing back the same actors to portray different roles (Emily O'Brien cough Blake Berris). I have seen interviews where Chandler said that he left to finish the degree program at UCLA that he put on hold when he accepted the role of Will but considering the popularity of WilSon, the timing did seem to be odd.
There seems to be an equal amount of drama behind-the-scenes at DOOL. The #metoo scandal at DOOL has exposed a lot of the poor management on the production side. When Freddie was doing podcasts with DOOL castmates, there was a lot of discussion about how poorly casting, particularly for contract roles, was handled.
If Josh Taylor were to pass away, DOOL would like continue using his corpse for as long as possible so that he continues to get a paycheck. Given his acting style, it would be weeks before fans even noticed that he was dead.