Historical/Time Travel shows

Historical shows with a smart male lead, where romance is not the main thrust of the plot. Any type of Isekai story where the mc travels in time or to a different reality is also appreciated. Most of the shows I watched in this genre are pretty underwhelming, where its clear that the setting is the mc's imagination, or like joy of life where in the first few minutes they tell us that none of the story is actually taking place, its just someone making stuff up. I liked My heroic Husband though, the mc commits to the new setting, doesnt really look to go back to his own reality, and is competently solving a lot of problems. Any recs are appreciated.

 Lou:

There are some but most have romance as the main plot. Nonetheless, even with romance, I'd recommend you to watch
Mr. Queen
Scarlet Heart Ryeo
Queen In Hyun's Man
Rooftop prince

some other  drama 

JIN (time-travel medical drama)

Just recalled one more which i am not sure if i will continue mid way through.. costume rom-com which is not really a genre i usually watch - Oh! My Emperor

Unfortunately the majority of time travel dramas tend to involve the woman travelling back in time. I'll try to avoid listing anything I see up above. But keep in mind these may or may not be for you, I'm trying to get you a list as complete as I can so I'm just throwing out anything that has a 'man travels back in time' plot device:

A Step Into the Past (Hong Kong 2001 with a mandarin dub. There's a remake as well but not as good)

The Myth (Mainland China 2010) 

Three Kingdoms RPG (Hong Kong 2012)

Time Slip Dr. Jin (Korean version of JIN I see listed by another user up above)

Tang Dynasty Tour (Mainland China)

Man Comes to Tang Dynasty (Mainland China)

Legend of Ace (Mainland China - might need VPN to Malaysia to watch  on Viu with Eng subs)

Nobunaga no Chef (Japan)

Borderline-ish:

Go Princess Go - (Mainland China) indie webtoon drama where man wakes up in body of princess.

Shuttle Love Millennium (Mainland China) - first half of 20th century

Ruk Laek Pop (Thailand) - first half of 20th century

Your Highness (Mainland China) - video game ancient fantasy China setting, more of a comedy

Joseon Survival (Korea) - the guy playing the male lead turned out to be rapist so he was replaced after a few episodes

Back to 1989 (Taiwan) - title makes it obvious it's not historical