The phrase "constantly losing" is correct and usable in written English.
You can use it to describe a situation in which someone is repeatedly losing something or failing at something. For example, "John was constantly losing items, so his parents had to be very careful when helping him clean his room."
Ingenuity is undermined, however, by his bad habit of constantly losing his own forged identity papers.
"If you look only at costs we are constantly losing competitiveness, but the price of inputs is not everything.
In his pre-match trash-talking, he had a go at the city for its "racist, constantly losing NFL team"—otherwise known as the Washington Redskins.
Since I'm constantly losing my lip moisturizers, I have about six or seven Burt's Bees Lip Balms scattered in my car, makeup bag and purse.
If there is no mobile signal in your area and you are constantly losing service, you may be able to terminate the contract for non-performance.
Anticipating his boss's every need, Mr. Lesser keeps "a bunch of extra spectacles of his in my desk because he's constantly losing them".
Arana's mother and father constantly lose their balance as they stumble over cultural minefields.
All animals need sodium and other minerals, since we all constantly lose these minerals through our kidneys and skin perspiration.
"Like the blocks of a child's game tumbling one into the other, forming a strangely obscure labyrinth in which guests constantly lost their way".
I remain myself, but I constantly lose my center, or what I thought my center was, or what my center will never be.
Hence, organisms occurring in water that has a lower solute concentration than their tissues (e.g., trout in mountain streams) will constantly lose ions to the environment as water flows into their tissues.
